POND CARE INFORMATION
(1) Water circulation
(3) Plant Filtration (Veggie-Bog Filter)
(4) UV Sterilization (& green water clarification)
(5) Pond Algae (Blanket, Green Water)
(6) Cleaning and maintenance
(8) Pond Care Bio Products
(13) Winter Pond Care (& leaves)
(14) Pond Bottom & Liners/Substrates/Yard Drainage/Repair
(15) Goldfish, Orfe, Fat Head Minnows and Koi
(16) Pond Predators
(17) Links to more expanded pond/aquatic care articles and related web sites too, such as Natural Environmental
(18) Koi Pond Video
(19) Complete Pond Articles Download
By Carl Strohmeyer-PAMR 35+ years experience
Keeping a clear garden pond in the warm or hot summer months involves these key ingredients:
Proper filtration (especially biological) and circulation, cleaning and maintenance, proper/optimum chemistry and feeding. It is also noteworthy that well built pond that is in harmony with nature needs much less maintenance.
This article will also deal with winter care tips, pond predators such as Herons and much more.
We have to remember too that a pond is living organism, unlike a swimming pool. Essentially a pond is an aquarium with the added bio load of leaves, pollen, run-off and other debris often being added to our aquatic environment.
Often this seems to be forgotten as I have come across many a pond over the years where the filtration was comparable to using a Hydro Sponge #1 filter designed for a 10 gallon or less aquarium for a 250 gallon aquarium. In other words, woefully inadequate.
Placement of your yard pond is important, despite popular belief a pond is best placed above any low spots in your property as drainage from a rainstorm (or even over watering) can foul your pond adding many unwanted nutrients and more. The sides of your pond should be built up at least a few inches. I also recommend a minimum depth of 24”. Obviously a raised patio pond will not have this issue.
Done right, a well set up and maintained pond improves the beauty of your home and garden and this regularly updated article, as well as the useful links to other resources such as Veggie Filters, UV Sterilization, and Pond Algae (green water) should help the reader achieve this with a garden or patio pond.
Please note that while I recommend specific pumps, filter, UVs, and other pond equipment; for the most part these recommendations are based on years of use (for reliability, efficiency, and economy) by me and/or other pond keepers and professionals I trust for their input; NOT what some pond supply distributor has suggested!
Please take most of these recommendations/suggestions as just that, as often there are similar products that might work just as well.
In the case of UV Sterilizers, I have VERY extensive experience, from designing, application, experimenting with controlled tests and more; so my recommendations for true UV Sterilizers (including specific brands there in) is based on this considerable experience and the use of equipment other than recommended will likely NOT yield the same results, especially based on email from those who have read this article but still chose a different path for this important equipment!!
For this reason, I stand by the suggestions/recommendation more strongly, again not that good results cannot be obtained with similar equipment, just that many of the Sterilizers I do suggest, especially the AAP/TMC lines, I have decades of experience with and this includes use of competing products that simply have not performed as well in 100s of applications I have been professionally associated with.
A good example is the TMC Professional 110 & 30 Watt True 'Category A' UV Sterilizers which along with others in this line of UVs has performed as well or better than any other comparable UV and at a better price & high longevity too.
Finally, my experience and the other professional pond keepers I get input from is generally for ponds up to 8000 gallons, so admittedly for much larger ponds, any prospective reader might find some great information here, but need to go further for added information.
Also PLEASE read the many additional resources already supplied here such as those cited for Veggie Filters or UV Sterilization.
This video provides a professional overview of pond requirements too:
If you have found this web site helpful (or the sister site Aquarium and Pond Answers), PLEASE consider a donation or purchase to help with the 1000s of hours of research and regular updates that go into these articles:
A general principle (not a rule) of about 50-200 gph per 100 gallons can work for this (A lower proportional gph for large ponds, a higher proportional gph for small ponds). This can be achieved with more than one water pump.
A large aeration device (air stone) coupled to an Air Pump can also aid in circulation and are especially useful for “lifting” (vertical circulation) water from the bottom of a pond when properly placed. Often an air stone/air pump combination is better than water pumps of greater gph for the aspect of vertical circulation (keep in mind that an air stone aerates the water by breaking surface tension, not by the bubbles in the water; the more surface agitation, the better oxygen exchange).
A large double air pump such as a Fusion 700, Million Air 600, Whisper 800, or Maxima with two air stones can circulate at a rate up to 500 gph. A way to check this is to place the air stone down a narrow PVC tube or aquarium lift tube, then place the top of the tube just above the water level and measure the rate the water fills up a gallon container (one gallon in 15 seconds= 240 gph).
With any pump (Water or Air), at least some form of circulation should be provided 24/7 so as to provide both oxygen and also to maintain a healthy bio filter (this also means a pump connected to a filter should run 24/7). Most pumps properly placed do not disturb fish, based on my experience.
General Pond Pump Recommendations:
For cross circulation (& lifting water to water features), a water pump is the primary choice.
To start with the Rio HF Pump line is an excellent line of pumps for most ponds from 300 to even 6000 gallons from my experience as these pumps have top notch head pressure, they are reliable and have flow rates up to almost 2000 gph.
What I have found is that even with larger ponds having multiple reliable and powerful pumps such as the Rio 32HF, I have more redundancy, more flexibility, and simply less "disasters" with a single "super large" pump pond.
As an example, I set up a 3000 gallon pond with three 2000 gph pumps feeding a fountain, veggie filter, two UV Sterilizers, and a DIY barrel filter and then a waterfall with good aesthetic flow.
Product Resource: Rio HF; High Flow Rate & Head Pressure Pond Water Pumps
In my many years of pond maintenance using many different brands, I have found that regardless of what a pump manufacturer or retailer tells you, ALL POND PUMPS ARE EASILY CLOGGED OR EVEN QUICKLY RUINED BY DEBRIS!
Whether you purchase one of our recommended pumps or use a pump you already have purchased; if you do not take steps to prevent debris from clogging your pump, you will be setting yourself up for future headaches and pond pump failures.
To protect your pump from large debris that can damage the impeller and impeller housing (this is a must with mag-drive impeller pumps), placing any water pump off the bottom of the pond on a cinder block or similar can keep large debris from quickly clogging pump intakes.
Please click on the pictures to enlarge for a better view
For further protection, you can place your pump in a DIY bucket (or box, etc.) pre-filter, or simply cover the pump with 1/2" to 1" rocks (porous lava rock is best).
Besides protection from debris, this added pre-filtration will provide some added biological filtration, but it does not replace a filter.
This is especially useful for pumps added solely to run UV Sterilizers due to added pre-filtration.
METHOD: Use a bucket, box, or similar container such as a Rubber Maid container large enough to house the pump; then add Volcanic Rock about ½” in diameter or larger, an outlet tube, then either seal the container with holes in the top OR simply leave the bucket, box, or similar container open with only the rocks/gravel exposed. A void space next to the pump intake will also extend time between rock rinsings.
To the left is a diagram of how this would basically work.
I recommend some sort of rock pre-filtration or similar with ANY submersible pump place on the pond bottom!! From my experience this GREATLY extends pump life regardless of any manufacturer claims as I have had very expensive pumps with so-called built in pre-filters fail in one season without this rock pre-filter.
Product Resource: Volcanic Rock Bio/Mechanical Filter Media
It is noteworthy that this rock will likely need to be cleaned ever few weeks to a month depending upon bio load and whether or a not a REAL filter is also employed.
Better is to incorporate this as part of a REAL bio/mechanical filter such as some of the ideas in our Veggie/Bog Filters article.
See the picture to the right, click on for further information.
For small to medium ponds (100–800 gallons): the SunSun HQB Series Pumps, or Rio 1700 all are proven in professional pond maintenance to be efficient and reliable, as well as reasonably economical pumps (the Rio 1700 has an available water Fountain Kit).
Both have sealed electromagnetic motors and ceramic shafts.
*Medium Duty Pond, Fountain Water Pump; SunSun HQB Series
*Taam Rio 1700 Water Pump
The lighter duty SunSun JP-066 can also be used in ponds, however I recommend using either the Filter version or making a pre-filter bucket to protect it due to the standard JP-066 pump not having a pre-filter (described below, which is a good idea for any pump unless a Hydro Pond Pre-Filter is used, which cannot be attached to a JP-066).
Many pumps, such as the Rio and SunSun can be mated to a Fountain Head with built in diverter then connected to a Filter (such as a small Pressurized Filter), and a UV Sterilizer (such as the TMC 15 Watt Pond Advantage PRO UV) for up to a 500 gallon pond
For medium to large ponds (500 – 1500 gallons);
For even more head pressure for high pond features (such as a water fall or spitter) that require lifts of much more than 6 feet the Rio HF Water Pump line is without comparison with their Vortex Rotor Blade (which can lift up to 14 feet), especially for the price.
The AAP JAP-8500 Amphibious Pond Pump can also be used for medium to large ponds (generally over 1000 gallons), especially when its multi-purpose versatility is needed such as running a larger fountain, powering a pressurized pond filter, and circulating water to a Veggie Filter all with one powerful pump
For Very large ponds; often the best way to go is with a heavy duty submersible pump with a directional vortex impeller or a pool/spa style pump that is designed for the harsh pond environment (some pumps cannot stand up to the debris and other elements of pond water circulation).
This said, my preference even with the 6000-8000 gallon ponds I have plumbed, I vastly preferred the redundancy of two or more heavy duty submersible or 'amphibious' pumps such as those suggested in the next paragraph over these pool/spa pumps such as the Seahorse.
This way if one stops/fails for whatever reason, your pond will still be circulating; nothing is more frustrating than coming back from a summer vacation to find a stagnant & smelly pond with a dead pump
As well two or more somewhat smaller pumps will almost always provide a better flow pattern and work better with most filters and UV Clarifiers.
The AAP JAP-18000 Amphibious High Performance Pump at 4755 gph is an excellent heavy duty submersible pump (pictured below). These high performance pumps are unique in their category in that besides excellent flow and head pressure, they have a double guard to protect the pump (both an outer and inner screen guard)
The AAP JTP-12000 pumps (pictured above) have now been out for a while, these have really impressed me as "the pump to have" for any medium to high flow submersible application due to reliability, flow and super high electrical efficiency!! The only negative with this pump is that while extremely efficient as per electrical usage, the head pressure is not as good as the AAP JAP pumps for a given flow rate.
For "out of the water" pumps, the Pentair SeaHorse line of pond pumps offers flow rates up to 4900 gph and are very well made reliable pumps that usually handle the harshest of conditions.
For these heavy duty 1/2 to 3/4 hp pumps, Heavy Duty submersible Pumps, or similar I have generally used 1.25 to 1.5 inch PVC pipe and then split the return pipe suing PVC ‘Ts’ and valves to control flow through other pond filters such as a Pressurized Filter and a UV Sterilizer. The purpose for this is to run multiple filters, UVs and/or to have a slower flow through these devices which generally work much better than at the high flow rate provide by this type of pump.
Even with a large pump like the SeaHorse, I still recommend another smaller one for redundancy in case of failure, and often for large ponds I simply use several pumps like the Rio 32H
Product Resource: Rio 32H 1590 gph Heavy Duty Pond Water Pump
Sometimes flexible/vinyl tubing will be difficult to connect, however by lubricating the connection, then heating the tubing, along with clamping with a standard hose clamp in some instances, this should not be a problem. This works for clear, black and ribbed tubing.
Aquarium and Pond Tubing Installation Tips
See this tutorial or help with tubing connections with your UV Sterilizer, Pump, Filter, etc.
For further Water Pump Specifications & Tips, please see:
Pond, Aquarium, Fountain Water Pump Tips
Dissolved oxygen is VERY important in ponds (partly for the Redox Balance). All oxygen is exchanged at the surface, so good surface agitation over the entire pond is best. Waterfalls, fountains, air stones all can achieve this.
Low dissolved oxygen levels and a low KH & GH (below 50/100 ppm respectively) affect your fish’ ability to perform osmoregulation & Redox Balance will be poor. If these parameters are poor, this will allow for much more opportunistic infections.
Further Reference: Aquarium Answers; Fish Osmoregulation
Make sure in winter months to de-ice and circulate water to the surface for optimum fish health.
For further information about GH/KH, please see this article:
CALCIUM, KH, GH, IN AQUARIUMS & PONDS
For further information about Redox Potential, please see this article:
REDOX POTENTIAL IN AQUARIUMS & PONDS; How it Relates to Proper Aquatic Health
Good filtration, especially biological is essential to maintain a healthy pond with the only "maybe" exception being with a “flow through/spring fed” pond.
Understanding the Nitrogen Cycle, which is the same in a pond as in an aquarium with the added input of debris from trees, wind borne, and sometimes wild/domestic animals adding to this strain on the bio system.
More than one filter is always best when possible and this includes DIY natural plant/veggie/bog filters which add to the aesthetics and are an enjoyable DIY project based on my experience.
As per the overview section of this article, most often ponds I have consulted for over the years are woefully under filtered for the given bio load.
Looking at it another way, if what you have for pond filtration (as well as pond pumps) is clogging quickly (requiring cleanings every week or sooner), your filtration IS INADEQUATE!!
Aquarium and Pond Nitrogen Cycle
Multiple types of filtration in combination are also excellent, such as these to name a few:
Readers might note that I did not include skimmers in my list above. While popular, I personally do not care for pond skimmers as these often tend to trap water lilies, hyacinth, and other floating pond plants all the while providing little to the quality of pond filtration (other than removal of floating leaf debris, especially in autumn).
I have found when I took over a pond care contract for a client that already have a skimmer, I would later disconnect the skimmer after adding a Veggie Filter. Part of the problem is many of the ponds I was called to consult on "after they were built" were built by "pool guys" and skimmers are great for pools, but not ponds and these builders often knew little to nothing about building a living pond, including a bog/veggie filter.
In the end, the pond actually was MORE clear with more natural looking floating plants too!
So avoid the sales pitch by many, do NOT purchase a pond skimmer by ANY maker as these are simply profit makers for the builders and retailers and long term professionals know that these are simply a device to take money out of your pocket!
The picture to the above shows a High Output Pond Pump embedded in loose volcanic rock (for added pre-filtration as noted earlier) connected to a Pressurized Pond Filter and then to a High Output Pond UV Sterilizer/Clarifier.
This picture displays how a large pump (as shown with the high flow VA Pump) can be utilized for more than one function, including multistage filtration, UV Sterilization, a fountain and even can be diverted for watering a Veggie Filter.
Please note that a control valve may be needed on both sides of the diversion ‘T’, otherwise the water will follow the “path of least resistance”, put another way if your water flow is too slow through the UV Sterilizer/Filter side of this example, it may be that the return is too high above the other return and simply lowering the return will solve this problem. As well after splitting a return line, the lines should not be combined later in the return. Please read the UV Sterilizations section for more on this subject.
I generally do not recommend the Pond Master Submersible & especially the Becket filters as they come out of the box; they clog easily and are not efficient filters unless modified.
HOWEVER the Pondmaster 1000/1700 can be vastly improved by unscrewing the screws in each corner and adding select pond capable volcanic rock biological filter media to this area under the tray (as the Pondmaster only utilizes two pads that only perform mechanical, some chemical, & NO essential bio filtration).
In fact the PondMaster can be an excellent bio filter for the money if purchased with this volcanic rock which increases bio capacity by over 500%, however MOST Sellers of this filter sell it on the "cheap" and unfortunately do not include this, in part because they have no professional experience and because they are attempting to maximize profits while keeping the price artificially low.
Volcanic Rock is excellent for this or BETTER yet would be SeaChem Matrix. Both of these would add considerably to bio filtration of your pond by adding to your filter.
In fact Pond Matrix provides the best internal macroporous surface area of ANY product and is an excellent compliment to a pressurized filter, waterfall filter, drum, or large sand/bead filters such as the AquaBead.
These macropores are ideally sized for the support of nitrifying and de-nitrifying bacteria. This allows Pond Matrix, unlike other forms of biomedia, to remove nitrate along with ammonia and nitrite, simultaneously and in the same filter and rarely if ever needs to be changed if properly cared for.
Pond Matrix also makes an excellent support for root development of aquatic plants and may be used for Pond Veggie/Bog Filters or in pots
I also suggest replacing the black carbon impregnated pad in the Pondmaster with a cut to fit Poly Pad and add carbon or Zeolite underneath the tray (also in a filter bag).
I prefer pressurized pond filters such as the SunSun UVC Pressurized or others for their efficiency and ease of hiding in the ground.
These filters include the popular Tetra, Lifeguard Pressurized, and Cyprio, which are excellent too, but tend to be over priced, especially considering Tetra charges almost $200 more for their UV feature when a separate and VASTLY better TMC Pond Advantage would be better (see the UV Section of this article).
Product Resource: Pressurized Pond Filter; SunSun with Volcanic Rock from AAP
The SunSun model pictured to the left, is not much different in design than other pressurized filters, rather what sets it apart is that it is also is supplied with highly bio efficient volcanic rock and and yet is still a lower price and is my recommendation!
Pressurized filters can be buried in the ground or place behind a water feature easily. Pressurized pond filters are very good bio filters especially when price is considered and these are also excellent mechanical filters.
However many if not most pressurized pond filters are sold with attached/built in UV Sterilizers which when the flow rate/dwell time is considered usually provides only some green water clarification and absolutely NO level one sterilization.
A SEPARATE UV such as the TMC Pond Pro Advantage is vastly more effective when plumbed properly including placed after an otherwise excellent pressurized pond filter.
Product Resource: TMC Pond Pro Advantage TRUE Level ONE UV Sterilizers
Further Reference, a MUST Read for pond keepers!!
UV Sterilization; Facts & Information; How Ultraviolet Sterilizers work in ponds
Do NOT confuse an aquarium canister filter with a pressurized pond filter, where as although a pressurized pond filter can be used for an aquarium, the use of an aquarium canister filter for a pond will result in failure since most aquarium canister filters have top mounted motors that will loose their siphon in most pond applications, as well an aquarium canister filter is not nearly as rugged in design for the pond environment (I had a couple of service calls many years back where customers attempted to utilize an aquarium canister filter for their pond and results were not good!).
SUGGESTIONS (based on pond size), please note a DIY Veggie Bog filter qualifies in ANY of these pond sizes:
Small or Patio Pond (under 250-500 gallons depending upon fish stocking and natural debris fallout);
For small ponds and patio ponds (ponds built in above ground "Rubber Made" or other similar containers such as converted horse waterers), large sponge filters are excellent bio filters and reasonable mechanical filters. They are inexpensive, easy to service, and simple to attach with either a power head pump or and air stone.
There now is a specific patented Pond Sponge Filter called the Hydro-Pond by ATI, with three models; one air driven, two pump driven. They are useful up to 1500 gallons and more can be used for larger ponds or in combination with other filters. The Hydro Pond IV also makes an excellent pre filter for pond pumps before water is circulated to another filter such as a pressurized filter.
For "patio ponds", these filters can perform very well since the only weakness is inability to handle large debris, but with patio ponds this is rarely a problem. In fact one client of mine with a 150 gallon patio pond had a small Becket pond filter he purchased at Home Depot that did not keep his pond clean, however when he switched to a Hydro Pond #2 his water while still somewhat green was much more clean and the fish could be readily seen.
I highly recommend the Hydro Pond filters for small pond owners on a budget, owners of patio ponds, or just to add redundancy to existing pond filters (often is larger ponds)
Product Resource: Patented Hydro-Pond; Sponge Filtration for Pond
A top notch (& unique) filter for ponds up to 500 gallons would be a TMC V2 1500 Fluidized Filter when combined to a pre-filter system as pictured to the left.
This system would work for larger ponds when multiplied such as two for up to a 1000 gallon pond.
The "SunSun CHJ-1503; Small Pond Pump/Filter", "Pondmaster 1700" are other rgood filter choices for small/medium ponds under 500 to 1000 gallons. These filters along with the Hydro-Pond Sponge and Fluidized are an excellent compliment to a Veggie Filter (which I recommend for any pond).
With the SunSun CHJ-1503 or similar Submersible Pond Filter you can easily attach a UV Sterilizer to the “diverter” valve (just above the filter and below the fountain head) for improved water clarity.
Another way to add filtration as well as a UV Clarifier is to use one of the before mentioned submersible filters along with the SunSun CUP series true UV Sterilizers that are a self contained filter, pump, and UV clarifier (these are mentioned in more depth in the UV section of this article). This would make for a simple "plug & play" redundant pond filter system for most ponds under 750 gallons
See the UV Sterilizer section further in this article for a diagram.
Medium Pond (250-2000 gallons depending upon fish stocking and natural debris fallout);
Bio falls such as the Savio Livingponds Filters are also excellent pond filters for medium and many larger ponds.
These filters can also be DIY (Do it yourself) or you can start with a basic Bio Falls “skeleton” filter (pictured to the left) and then add bio filter media (such as Volcanic rock) and place a Polyester Media on top.
However if you have purchased a unit such as Savio Livingponds Waterfall filter, you can add extra media to meet your pond needs and possibly save money. For instance I have often substituted Volcanic Rock of different sizes (depending on coarseness of filtration needed) for bio and mechanical media in these and similar filter.
This article about Aquarium filter media can also be applied to ponds:
Aquarium & Pond Filter Media, Material; Mechanical, Bio, Chemical
Plastic grates and even rocks formed into basin can be used to construct the bio and mechanical filter for flow through either prior to a water all or after (prior is more common). If a cement product is used in construction, I recommend sealing it with a water proof sealer available at most Home Improvement Stores.
Use of volcanic rock for bio filtration and Coarse Polyester Media (pictured to the left) can help with the filtration need of your bio falls project as well as other similar projects such as a Veggie Filter pre-filter trap.
Product Resource: Coarse Poly Pads; Excellent for DIY Pond projects
*As noted earlier, Pressurized Pond Filters are an excellent choice for medium ponds. These can used with other filters for improved filtration and redundancy or even larger yet ponds.
You can also use multiples of Pressurized Pond Filters for larger ponds. As well even a smaller pond can utilize these simple yet effective filters, especially where the bio load is high.
This is probably one of my favorite pond filter types to use either by itself, in multiples or often with other pond filter types.
Two aspects of this filter type I like is their ability to go inline from the pump to any water feature, such as a water fall, while maintaining water pressure (no need for gravity feed). The other aspect I like is these can be partly buried to improve the pond aesthetics.
Product Resource: SunSun Premium Pressurized Pond Filter
*Another filter that works well with small and many medium sized ponds is the barrel style filter by Tetra and Coralife; these are excellent bio filters, but poor mechanical filters. They also are hard to hide as they have to use gravity to return water back into the pond after the pump first supplies these filters with un-filtered water.
This filter too can be a DIY project using a large sterilized drum.
Pond Filters of Note & Larger Pond Filters:
*A filter that is also used is pool style sand filters. I have used these filters in many of my largest pond installations (over 5,000 gallons).
Despite what pundits for these over priced monstrosities say, they are not originally designed for ponds. The fine sand therein will often compact and the water then tends to follow the path of least resistance thru these filters, leaving areas on anaerobic bacteria producing poisonous Hydrogen Sulfide.
DO NOT be fooled by their high price (often well over $1000), I can tell you from vast experience with them that they are not worth it!!
That said, if you already have one, I recommend adding volcanic rock and/or SeaChem Pond Matrix to improve upon this problem and also allow for nitrate removal via de-nitrification.
*Fluidized Sand or Moving Bed Filters;
These types of filters are purely for nitrifying (removal of ammonia & nitrites but not nitrates), however they are excellent at performing this task (and in fact the BEST)!
I do recommend pre-filtration of some sort such as coarse rocks near an intake or at the very least a coarse mesh screen to allow for maximum effectiveness.
Of these types, the Fluidized is the most efficient from what I have found, especially the third generation models such as the TMC V2 1500 Fluidized Filter. However these standard Fluidized Filters are only capable for ponds up to 500 gallons unless multiples are used or as a compliment to other filters.
Product Resource: Premium Fluidized Sand Bed Pond, Aquarium Filters
The best is the TMC Pro Pond FBF80 Fluidized Filters with the capacity to handle 176 lbs of bio mass respectively (this is a LOT of fish!). This works out on average to a 2500 gallon to 5000 gallon pond. Their size alone belies their large pond capacity with the FBF80 measuring 61 inches tall and 13 inches wide.
Future Product Resource: TMC Pro Pond FBF80 Fluidized Filters
With either of these filters, I would strongly recommend a DIY Veggie/Bog filter to provide nitrate removal via plant roots end de-nitrification.
DIY Pond Veggie, Bog Plant Filters
The picture to the left demonstrates a DIY barrel type pond filter that could be built by anyone with reasonable DIY abilities.
I would suggest using volcanic rock and/or SeaChem Pond Matrix in one of the filter media layers with poy pads or other mechanical media types in the other layers.
Volcanic rock makes an excellent filter media for DIY pond filters, waterfall filters, veggie filters (for the base), and many types of commercial filters such as the Savio.
Please click on the picture for more information.
For information about different filter media that can be used in your pond filter, please visit this article:
Aquarium and Pond Filter Media
This is a very important part of pond keeping and filtration.
A well planted and diversified planted pond is VERY important for clarity (including green water control), pond and fish health, and even fish breeding.
Any plant with a good root structure that grows fast and has the majority of their leaves above water is a good candidate to start with.
I recommend water iris for their strong root structure, fast growth, great nutrient absorption, and a great place for baby fish (fry) to hide feed and grow (if you use an “in pond” Veggie Filter).
There are many other excellent plants as well such as Cattails, Sweet Flag, Parrots feather, Bluebells, Umbrella palm, Papyrus, & bull rush. Make sure these types of plants (plants with roots in water and leaves above) are planted in an area of good, but not strong water movement. This ensures that they will do their job as plant filters.
Other plants such as lilies and hyacinth are reasonable for nutrient removal too, but NOT at the rate of iris and similar plants. These plants also do not have the root structure that will aid in the rapid removal of nitrates and ammonia, and thus should not be a part of a true Veggie/Plant filter.
However, these floating plants are useful for shade, which will slow algae growth.
I will often place this plant/bog filter in an area of water constriction between two ponds or in an upper waterfall area with low to moderate current. In smaller Ponds I will just place this plant filter in a corner of the pond with a small water current applied to the planted area.
I prefer my plant filters within the pond as these look more attractive in my opinion and give the fish fry a place to hide (except in the case of the waterfall or cascade plant filter).
The area of the Veggie Filter should be relatively shallow as well to force water movement over and through the roots.
The key is also water movement along with a good media (Volcanic Rock is preferred) around the roots/tubers. While the flow does not need to be 'fast', there should be a definite flow of water through this Veggie/Bog filter. Often a lack of flow and use of a good media such as volcanic rock is why some Plant/Bog filters fail to work very well and algae such as hair algae will then grow out of control.
Using PVC pipe with holes drilled and then embedded in this volcanic rock with plant roots that then feeds into a True UV Sterilizer makes all the difference in the world (The cheap UV Clarifiers sold via Amazon, eBay, Lowes, Home Depot, etc. do NOT pass a true UV Sterilizer).
In other words, construction and proper equipment is key to the success. If done correctly, this is a DIY filter that often far exceeds anything you can purchase or at the very least will compliment any other pond filter.
Other methods include separate veggie filters in containers or pools. I am not as fond of this method for the reasons above, however these can work.
Click picture above to enlarge
Here is a video showing how the proper construction of an "in-pond" Bog/Veggie Filter coupled with a TRUE UV Sterilizer (in this case the TMC Pond Advantage, do not use an economy UV) can make a big difference in just a couple of days:
FOR MY FULL VEGGIE FILTER ARTICLE, please visit this link:
POND VEGGIE (BOG PLANT FILTERS)
This article includes much more information on this subject, as well as links to resources for bog plants and similar.
The bottom line is few ponds in my opinion are truly complete without a "Veggie/Bog Plant Filter" as they can make a big difference when done right in pond clarity.
As an example, I had one pond I built for a client that had such a large and efficient Veggie Filter that it stayed clear without the UV Sterilizer running.
For those who read this, please note that my emphasis of the use of Veggie filters is not driven by financial gain, as although I obviously list products to sell through my many articles (as a means to pay for the time to keep these articles up to date), I have little to gain since Veggie Filters are primarily a DIY products.
The picture above/right is of a pond with relatively new Veggie/Bog filter where water flow was also recently added improving the results.
Although not always necessary in a well planted, well shaded, well filtered aquarium; these devices are still very useful if only for the benefits of a true level one capable 'Category A or B' UV Sterilizer that goes beyond clarification.
True UV Sterilizers help not only with algae control, but also with disease prevention, and the Redox potential by lowering oxidative stress (which is important for fish health and proper filtration). While lower priced UV Clarifiers commonly sold via discounters online or big box stores like Home Depot ONLY help with Clarification and even then do a lessor job clearing a pond
The time it takes to clear a green pond with a UV Sterilizer/Clarifier can vary greatly from 1 day to a couple weeks to even never!
The reason for such wide variance is due to lack of adequate filtration which includes a good bio filter such as a veggie filter or use of de-nitrifying material/products such as SeaChem Matrix or Volcanic Rock.
This is why the formula I use to match a UV Sterilizer/Clarifier to an Aquarium or pond can be "off" by 50% or more, since this formula along with all reasonably honest manufacturer recommendations ASSUME a healthy bio filter. In other words, if a UV Sterilizer is rated to clarify a pond of say 1000 gallons, if its bio load exceeds the bio capacity of filtration, it may take a UV Sterilizer rated for 2000 gallons+!!
It is also noteworthy that the same UV or even a lessor UV may clear a pond one season and not the next; this is quite common as a pond matures, in particular in a pond with inadequate filtration!
Another common mistake is to simply run even an effective true "Category A or B" UV such as the AAP/TMC Pond Advantage, AAP Pro Clear Pond, or Emperor from just a water pump with no pre-filtration prior to entering the UV Sterilizer. This increases water turbidity considerably and thus lowers UVC effectiveness also considerably. Simply placing your water pump in a bed of volcanic rock can often work as a pre-filter, so can a Hydro Pond Sponge Pre-Filter.
Further Reference: UV Sterilization; Water Turbidity
As well longer periods or never clarifying can simply be due to an inadequate UV and/or one that is properly plumbed.>
It is also noteworthy than many so called UV Sterilizers are in fact ONLY capable of UV Clarification and therefore should be labeled as UV Clarifiers, but are unfortunately improperly labeled as Sterilizers.
This is an important point, even if you are not interested in improving water chemistry via Redox or killing disease pathogens, as a true UV Sterilizer can "Clarify" a pond much quicker than a UV that is ONLY capable of clarification. Also a true UV Sterilizer often works for green pond clarification when a UV clarifier fails due to high bio load, excess sunlight and other factors over load these devices limited capabilities.
For the UV to properly function in a pond for green water control (UV Clarification), the flow rate should not exceed 40-50 gph per watt of UVC in most Compact UV Sterilizers (such as the Tetra, or Terminator), or 50-70 gph per watt for most higher dwell time straight tube UV Clarifiers (some super high efficiency/dwell time UV Clarifiers such as the AAP Pro Clear UV30/UV55 can go to over 70 gph per watt).
Keep in mind these numbers are for UVC Clarification, not level 1 sterilization (which requires slower rates and higher pond or aquarium turnover).
Product Resource: TMC Pro Clear UV30
The VERY BEST Pond UV at ANY Price!
In larger ponds with high flow rates I often recommend more than one UV sterilizer, with a by-pass from the main line to control flow rate, then each unit connected in parallel for best results, although in-line can work too, just not as effectively. Often a separate, slower pump (with a pre-filter) installed for the sole purpose to run the Pond UV sterilizer is the key to success when the main pump line runs at too high a flow rate for the UV to be optimally effective.
For this reason, I also do NOT recommend the popular filters with built in UVs as your Pond's sole UV Sterilizer/Clarifier.
The flow rate is usually too high to work properly. As well, the design of most I have seen and used have too high a gap between UV bulb/quartz sleeve sterilizer compartment wall, which is generally not adequate for good UVC exposure. The FACTS are that these filters with built in UV lights are UV Clarifiers AT BEST, and even then poor UV clarifiers.
A separate UV is always best! I have maintained ponds with UVs in filters and UVs separate and the difference in water quality in the separate UV ponds is significant!
However, do not take this advice to mean no pond filtration is needed, only a water pump and a separate UV run by this water pump is NOT adequate.
For CORRECT UV Sterilizer function, the pre-filtration of water prior to entering the UV is a MUST (even if just encasing the pump with volcanic rock as shown near the beginning of this article).
What is also noteworthy is that while a basic UV Clarifier can clear green water when properly installed, it WILL often takes days when under the SAME conditions a TRUE level one or higher UV Sterilizer (especially a high dwell time model) can take just a day or two or even as little as just hours while also having the bonus of improving fish disease resistance (via improved Redox Balance).
For more information about correct Pond UV sterilization and how it works please visit this site;
Many times I have heard of complaints that their UV did not help with algae control, when I checked this clients pond, I found inadequate filtration and an improperly installed UV sterilizer. Even a properly installed True UV Sterilizer cannot over come poor filtration and a poorly planted pond. As well, many manufacturers make claims of high flow rates that are impossible for proper contact time.
Another common problem I have encountered is a poor circulation pattern where-by the water pick up for the UV Sterilizer was near the water return, with the result that 3/4 or more of the pond water never made it into this flow pattern for proper UVC Sterilization.
To maintain a proper flow rate per watt per gph, connect a ‘T’ in line to your high flow rate pump, from there a reducing bushing (Ex. In 1-1/2” PVC I would step it down with a 1-1/2” by ¾ bushing), from there an in-line ball valve, from there to your Pond UV Sterilizer, then back to your pond or water feature (such as a waterfall or spitter).
Another option is to split the outflow from a large, high output pump and place a UV Sterilizer on each line.
You can also simply add a separate lower rate pump just for your Pond UV Sterilizer.
These diverter valves are listed/sold here: Pond/ Aquarium Plumbing Parts
Please note that these diverters only represent a fraction of PVC sizes and combinations, as well a ball valve may also be necessary on two sides of the diverter if head pressure is too high on the UV Sterilizer return side.
Often it is difficult to determine the flow rates of larger high pressure pond/pool pumps rated in HP (horse power) rather than flow rates that are occasionally used in larger ponds.
This diagram can help determine flow rates at certain head pressures if you own such a pump (please click to enlarge). It is noteworthy that these pumps in 1/2 HP or higher do not even loose flow to head pressure until after 12 feet of head.
Here are a few solutions if the flow is too slow through your UV Sterilizer:
This diagram shows a Via Aqua BH2000 Filter/Pump (similar to the before mentioned Pondmaster or SunSun Pond Filters) connected to a UV Sterilizer via the built in diverter valve. This valve is common to most similar fountains and filters such as the Pondmaster 1700, SunSun CHJ-1503, and many more.
For Small Ponds, self contained Internal/Submersible UV Sterilizers are growing in popularity, however I would caution prospective buyers that the first generation models have problems with electrical failure and are not efficient.
Product Resource: Submersible UV Sterilizer Pump, Filter
I would also point out that while these UV/Filters do provide some filtration, this is intended primarily for pre-filtration prior to water entering the UV-C chamber.
For larger ponds (over 2000 gallons) often placing two UV Sterilizers such as two AAP/Terminator 36 Watt UV will be more economical than one larger UV Sterilizer as when used with separate pumps, the flow pattern is often better, therefore the pond "turnover rate" (how often the entire pond water passes through the UV Clarifier) is generally slightly higher than one unit of say 75 watts that often costs more than double the price as well.
Product Resource: SunSun CUV-136 Compact UV Sterilizer
For very high volume pumps or extra large ponds units such as the TMC Professional 110 Watt UV Sterilizer would be an excellent choice.
Product Resource: AAP/TMC Professional 110 Watt True UV Sterilizer
I should also note that spending more money for a pond UV Sterilizer/Clarifier with wipers or HO UV-C bulbs is often not money well spent, as the wipers are often gimmicks that easily break and do little even when functional. As well HO (high output) UVC lights often are very short and even with this higher output, these are often still not enough for the water flow that is usually applied to these UVs as per dwell time
Better is a unit with long exposure such as the before mentioned TMC Professional 110 Watt UV Clarifier or a couple of TMC Pro Clear UV30s as compared a Smart HO Two-Lamp 100 Watt UV Sterilizer.
The TMC Pro 110 Watt is not only vastly less expensive, it is a superior UV Sterilizer in terms of UVC exposure and performance.
For an article that deals with the question of pond filter placement in relation to a UV Sterilizer (as well as many other aspects of UV Sterilizer use), please follow this link:
Another important consideration with the use of ANY UV Sterilizer for outdoor pond use is protection from direct weather exposure.
My suggestion is to cover the UV Sterilizer with flat rock (such as pictured) or suspend the UV in a structure that protects the UV from direct weather, including sunlight.
Further Information: Actual UV-C Emission from a UV Bulb; Aquarium or Pond
Product Resource: True Level Capable Low Pressure UV bulbs, Page 1
If you have problems with a new UV Bulb firing, please see this video and/or read this article:
Finally, while I recommend a UV Sterilizer/Clarifier for most ponds, I find that many pond keepers are too dependent upon this device where as if the UV ceases to function the pond immediately turns pea soup green.
Further Reference: DIY Pond Veggie Filters
 POND ALGAE (Green Water and Blanket weed)
For MUCH more about the control, prevention and treatment of pond algae, please read this article:
Also see this article for information specific to Cyanobacteria:
Cyanobacteria in Ponds, Aquariums
In a healthy pond, with a properly functioning nitrogen cycle, water changes can be minimal. I still recommend a water change of 10-20% per month on a healthy, fully functional pond. In a newer pond larger and more frequent changes may be necessary.
If a lot of leaves fall to the bottom of the pond vacuuming them or raking them out is important to prevent organic buildup.
Water changes also will help with pH and KH if your tap or well water is slightly alkaline and has a KH above 80 ppm.
Your pond filter should also be part of your pond cleaning schedule. With a pressurized filter such as a Pressurized Pond Filter, I recommend cleaning and rinsing once per month during pond season or more often if the flow rate slows down.
Veggie Filters should cleaned and trimmed at least once per season.
 POND CYCLING:
Generally speaking this process is about 99% the same as aquarium cycling, so I would strongly recommend reading this excellent article:
I would add in addition to this article that the process of cycling in a pond takes 6-8 weeks in warm months, but cooler temperatures such as a pond under 60 F can delay this process.
 POND CARE BIOLOGICAL PRODUCTS
For bio bacteria maintenance, products such as AAP/SeaChem Pond Stability, which contains "Natural Environmental Beneficial Bacteria", is useful for aiding in the breakdown of organics and maintenance of the pond's natural nitrogen cycle.
However if there more accumulation of mulm/sludge on the bottom of the pond, AAP Pond Zyme would be a better choice (or combined with Pond Stability).
For water clarity, PondCare Barley Clear is another useful product that uses the natural abilities of barley to control algae blooms as well as the natural properties of peat to buffer pH for a more stable environment.
I have used and sold these products in my Aquarium and pond Maintenance business with fair to good results. They are good at aiding in the breakdown of sludge and improving filter efficiency, however it is not a cure all for poor filtration and pond maintenance and some claims in my opinion are somewhat over blown.
Of these products, the newest and most effective is SeaChem Pond Stability followed by Natural Environmental Beneficial Bacteria Blocks are easy to use and when used properly can be a compliment to other good pond maintenance procedures.
It is important to note that many of these products are primarily Heterotrophic Bacteria and other enzymes, NOT the nitrifying Autotrophic bacteria necessary for a healthy nitrogen cycle (although Stability has facultative bacteria too & is more helpful to pond cycling).
 POND CHEMISTRY (GH, KH, etc..);
This is important not just for fish health, but also for algae control as well.
A good electrolyte level is an important aspect of pond chemistry many miss
This is maintained by a constant supply of mineral positive ions (Cations) will also help maintain a good Redox which in turn aids in water clarity, not to mention the very important aspect of good osmotic function in fish for long term health.
If your GH is low this can be a problem (with a stable pH) during the hours of the day when photosynthesis is high, even with an adequate KH.
Products such as Wonder Shells (or Sea-Lab for larger ponds) can help with supplying essential mineral cations as well as oxidative stress/poor osmoregulation, ammonia, & stress from transfer.
For more about how this affects algae, please follow this article:
For more about Alkalinity and hardness in ponds, please read this outside resource:
Generally most Pond Fish such as Koi and Goldfish like a higher ph of about 7.8 (although a pH in the range of 6.8 to 8.0 is often acceptable). A well planted stable pond usually does not have problems with too high or too low a pH.
Product Resource: Marine Buffer; Excellent for Pond Use
For too high a pH (rare), these are cost effective ways in a pond:
 POND FOAM:
Foam around waterfalls and other water features is not uncommon, however if this is a persistent problem, there may be other issues at play in your pond.
For minor problems, especially foam that occurs only around water features, products such as Jungles No More Foam can be useful for blocking the waters ability to foam.
Feeding a quality diet can be beneficial for growth, breeding, color, and even the environment as there is less nitrogenous waste to add to the water column.
This is a broad subject that is beyond the scope of this article, so I would suggest reading more specific articles, here are a few suggestions:
This is far a complete list, however many more can found in our Aquatic Information drop down list in the header bar or at Aquarium/Pond Answers.
One important point I will make and that is the importance of changing water (at least 25%) prior to every single treatment.
The reason is that ponds in particular generally have a high content of dissolved organics, floating algae or similar bio substances, much more so than the average aquarium. These organics will absorb many treatments, especially chemical treatments such as those that contain Malachite Green (such as Quick Cure, which is a very effective pond treatment of many small pond parasites).
By changing water first, this allows for more medications to be delivered to the pathogens causing disease, as well this will generally improve water conditions which in turn helps the fish fight off the infections/infestation better. This can also lower the amount of medication that might be needed to treat your pond as well.
I recommend this water change prior to any and all treatments.
A few suggested pond use treatment products that are biologically safe when used correctly, in particular for prevention are:
 WINTER POND CARE;
It is important in winter to keep at least a small section of your pond open for proper exchange of gasses (O2, CO2), if water can still flow into the pond through a water or aeration device, that will work. A minimum depth of 24” (deeper in climates where soil temperatures drop below 32 F) will provide enough water space under the ice for fish to hibernate (even in the coldest climates, ice will really extend more than 6-8”).However if you live in an area of hard freezes, you may need heaters or a device such as this Pond Master Deicer:
If an aquarium heater is adapted to your pond, make sure that there is circulation near the heater and keep in mind that all you are attempting to do is raise the temperature above freezing, so generally only about 1/2 watt per gallon is all that is necessary for most ponds to keep above freezing (assuming adequate circulation).
For example, a 300 Watt Heater should work for most 600 gallon winter ponds (unless you live in the arctic circle). Make sure to protect the heater from fish or turtles that may break the heater using a cinder block, brick, large rocks, etc.
For a smaller 100-200 gallon pond, such as patio or prefab pond, generally a 200 Watt or smaller heater is all that is necessary to take the edge off the cold.
Product Resource: Via Aqua Premium Quartz Heaters
An aeration device or pump placed about midway from the surface/bottom that circulates upward generally will keep an area of the pond surface free of ice and allow proper gas exchange. In deep ponds over 5-6 feet (1.75 -2 meters), thermal layering, called thermoclines, may exist. This acts as sort of an “inversion layer” similar to how smog gets trapped in the air in Los Angeles. This traps CO2 and Hydrogen Sulfide near the bottom which is dangerous to fish and in this case you need to add water pumps or aeration devices at the bottom.
*Million Air & SunSun Air Pumps
*Pond & Aquarium Pumps
Sometimes removal of fish in the winter is also necessary when the pond is very shallow (under 18-24 inches). I recommend avoiding this if at all possible with larger mature fish as this can injure and often cause more stress than simply improving your pond to deal with winter conditions.
 POND BOTTOM, CONSTRUCTION, REPAIR, SUBSTRATE:
Construction and make up of your pond can be done in three different ways (and there is no one best way; the best way fits your pond size needs, climate and budget).
It is not unusual for a pond to have a leak from either time, poor construction, weather damage, animal damage or "you name it".
 SPRING FED POND (Also water level maintenance);
If you live in an area of natural springs or have creek flowing nearby, this can make for a very healthy, clear and natural pond.
Another method for adding water simply is a float valve. These will add water due to evaporation or loss of water by other means and can even be used with flow through system to automatically regulate water level. Here is a picture of such a float valve by Hagen (Laguna).
 KOI, GOLDFISH, ROSY-RED FATHEADS & GOLDEN/BLUE ORFE;
The Golden Orfe (& Blue), is suitable for ponds. It can grow up to 2.5 feet but usually stays near 1.5 feet. It is a long, slender, bullet-shaped, schooling, orange fish often with black dots on its head and back. Orfes are native to Europe and were derived from the ide which is a silver predator. They need lots of room generally live 10 20 years, however this has not been established.
The Fathead Minnow and Rosy Red Minnow are popular fish for ponds and even aquariums. These small graceful fish do well in similar water conditions as Koi, Goldfish, and Orfe which is higher GH and a pH between 7-8, and prefer temperatures between 50 75 (10-24 C), although they can survive between 33- 100 (1- 38 C).
 POND PREDATORS:
I found Heron decoys such as this one by Hagen: worked well at not only scaring away Herons, but other predatory birds as well such as Cormorants, Owls, etc. (I might note that these decoys do NOT work in breeding season which early March 'til late May where they actually may attract Herons!). I also suggest moving the decoy around as Herons can quickly learn that this is a fake Heron.
This Alligator decoy is another Heron deterrent that others have used successfully (I have not used this method myself, so I cannot personally vouch for it, but it certainly seems like a good idea and I trust those who have claimed to use it successfully).
If you have found this site helpful (or the sister site Aquarium and Pond Answers), please consider a donation to help with the 100s of hours of research and regular updates that go into these articles:
For our business partner webpage: Business Partners; Great Links
| Pond-Algae |
| Basic_Aquarium_Principles | Basic_Saltwater | Aquarium_Disease | Aquarium_Lighting | Goldfish_disease | Aquarium_cleaning | Nitrogen_Cycle | Redox_Potential | Clear-Pond | Aquarium_Filtration | Aquarium_Medication | Aquarium UV Sterilization | Vibrio_Aeromonas | Aquarium_Ich | Columnaris | Aquarium-KH | sponge_filtration | Aquarium-Plants | Quality_Fish_Food | Oodinium |
| Return Home | Aquarium_Information | Aquarium Products | Downloads | FAQ | Other | Contact Us | View Cart |