Best Koi Pond Filter Systems – Top 5 Picks of Koi Tank Bio Filters

Product TypeProduct NameCheck Price
pond_pressure_filterGoplus Pond Pressure Bio Filter 4000GALCheck Price on Amazon
tetra_pond_filterTetraPond Filter Bio-Active PressureCheck Price on Amazon
oase_pond_filterOASE BioSmart 5000 Pond FilterCheck Price on Amazon
grech_cpf-2500Grech CPF-2500 Pressure FilterCheck Price on Amazon
laguna_filtersLaguna Pressure Flo-Clean 2100Check Price on Amazon

TetraPond Filter Bio-Active Pressure

TetraPond Filter provides active mechanical & biological filtration to maintain the healthy water pond. The filter systems is equipped with the bio-activators which provides a large surface area for unrestricted water flow without any problem.

TetraPond Filter Bio-Active Pressure

OASE Bio Smart 5000 Pond

The OASE BioSmart 5000 Pond Filter is innovative and efficient. Maximum oxygenation is provided by the filter with mechanical & biological filtration. The sludge drain is provided with the Koi pond filter systems for easy removal of dirt & debris, no need to manually unclog the water drains as Bio smart feature does that all for you.

OASE Bio Smart 5000 Pond

Grech CPF-2500 Pressure Filter

The Grech CPF-2500 pressure filter is the best, not only does it outperform some of the pricey filters, but it also requires less maintenance than some of  more systems

Grech CPF-2500 Pressure Filter

Laguna Pressure Flo-Clean 2100

The pond water is kept healthy & cleaned having a high-performance filtering system is the Laguna Pressure Flo-Clean 2100. Laguna’s Max flo gives active mechanical & biological filtration. This great inline  pump and filter can be added to most pond installations by simply cutting a waterline from the pond pump to an existing water feature, like waterfalls or streams.

Laguna Pressure Flo-Clean 2100

Goplus Pond Pressure Bio Filter 4000GAL 13W UV Sterilizer


A new pond? No Problem. Here is the new Goplus  filter which improves the water quality to give a healthy & happy life for the fishes living in the pond. The filter absorbs 13 Watts from the electric socket. This has proven to be a great pond filter systems from the beginning.


More about Aqueon Aquarium Filter

The water is crystal clear with no exaggerations and an issue with the capstones, they were shaking and also dirty when laid – and that will be an issue in your part. A recommendation that put clamps on all hose connections when you complete the installation and use good quality hoses – nothing that will compress or break easily.

Go plus koi pond filter is a very valuable tool to fight bacteria and Algae. This pond filter will improve the clarity of the pond water within the first few days. Setup was easy and this filter was much less expensive and more efficient compared to other koi pond filter systems.

Note that 1-1/2 inch Fernco couplings can connect hoses directly to the threads, eliminating the need for adjusting for those stepped conical fittings.

Fernco has straight and 90° fittings, so it’s just a matter of finding good 1-1/2′ O.D. hose, and fitting for the pump, depending on the brand, a 1-1/2″ or 1-1/2 to 1-1/4″ Fernco might fit the outside of the pump’s hose fitting

A couple of things that were troubling in the Koi pond filter are

1. The instructions were not proper, the instruction booklet is worthless.
2. The “dirty water” discard spout for plants sounded good but you will end up diverting back to the pond.
3. Even after turning off the koi pond filter, it discards too much water nonstop flooding the flowerbeds
4. At first few tries, it leaked like a sieve out of the top. You have to make sure the rubber seal is perfectly set and in place.

TetraPond Filter Bio-Active Pressure With 9W UV Clarifier


It has filtration which flows down to the bio activators & removes debris & dirt from the water. The UV clarifier does a great job in removing even a single particle of algae from the water pond to keep it fit. The koi pond filter can be hidden behind rocks or bushes and can even be buried partially.

Also check out Sunsun Canister Filters

If you are burying the TetraPond Filter, place a plastic tub in the hole. Allowing easier access to the latches, and easier to remove the koi pond filter for winter storage. Plastic tubs are cheap and can be found in any hardware or houselling stores. 20-gallon tubs are ideal for this use.

If you have plenty of oxygenating plants like – lily pads, parrot’s feather, aquatic mint then TetraPond Filter is best for keeping algae away from the pond water.

Installing the filter is easy: connecting your pump to the Koi pond filter systems inlet with tubing and then more tubing from the outlet to where you want it to flow. Make sure to purchase some Teflon Tape to wrap the inlet and outlet adapters and a few Hose Clamps based on the size of your tubing for a waterproof seal.

It will take 2 days to make the pond water crystal clear with the help of UV light. This filter does not remove all the algae in the pond, the UV light sterilizes the algae so it cannot reproduce. It makes it a lot easier to maintain though and does not disappoint.

There is a convenient knob on the top of the unit to backflush the unit if it gets clogged. Simply turn the knob from one direction to the other and it will backflush all of the dirt and debris from the filter out of the unit, turn the knob back on to resume normal flow.

TetraPond Filter works in the following ways

-Water flows from the pond to the pressure filter
-Water is filtered according to the process
-After that water is forced to the center tube where the UV light destroys all the microorganisms & also they can’t reproduce, they are filtered removed.
-Filtered water is again sent back to the mainstream or pond.

Check out 10 Gallon Fish Tank Filter

All in all, we are very satisfied, the price is a bit steep but definitely the cheapest around and completely worth it in the long run.

OASE Bio Smart 5000 Pond


The Koi pond filter contains beneficial bacteria which is responsible for the nitrogen cycle & also removes ammonia from the water. The OASE BioSmart 5000 Pond Filter has Nature-friendly technology with positive results for local wildlife and fish stock.

With a built-in cleaning indicator and water temperature display, the unit requires minimum maintenance. The OASE BioSmart 5000 Pond Filter UVC 1600 with included UV Filtration is for ponds up to 1,600 gallons; the Bio Smart 5000/10000 for up to 10,000 gallons. For maximum effect, it can be combined with the Vitronic 18 – 36 Watt UV Clarifiers.

You will be amazed by this filter, It looks like it’s an indoor aquarium, that’s how clean the water is. Clean the filter systems more than once a day about 2-3 times a day for a week. Takes 7 minutes max to backflush the water from the Koi pond filter. The flow is excellent. Shipping was fast and the product works great.

The pond size can be 20′ x 10′ x 3′ deep with about 20 koi fish, some are pretty big. You can use the same flex line for drainage so that dirty water doesn’t flow back into the pond. You can add a 3″ PVC elbow, coupling and about 4′ of straight pipe to get the water back into the pond.

Cleaning the filter it once a day or every other day doesn’t create a problem. Your pond will look better than ever. It looks like a green soupy mess. You will be amazed your Koi fish lived through it. After only one week you can almost see the bottom and, confident enough that the biosmart 5000 will continue to clear your pond water. You never have to buy another maintenance item to clear up sludge ever again!

Grech CPF-2500 Pressure Filter with 13-watt UV Sterilizer


The Koi pond filter systems is a little complicated to assemble the first time around. It’s equally as complicated and also time-consuming to break it all apart to do a full cleaning. It worked perfectly and only took about 20 minutes start to finish.

Read more about undergravel filters

The backwash and self-cleaning filter systems is genius! The filter pads are shaped like cogs with notches around the outer edges. Connected to the cleaning handle is a triangle shaft that goes the entire length of the koi pond filter which fits tightly into the notches on the filter systems.

When cranking, the shaft uses the notches to rotate all the Koi pond pump and filter at one time while simultaneously pressing down into each filter and squeezing out the surface crud which then gets washed away through the backwash valve, it is brilliant Repeat the sets until the water is no longer thick and dark while cranking.

After installing the Grech CPF-2500, the pond has gone from pea soup to almost completely clear. If your pond is small about 800 gallons but so muddy looking that you couldn’t see the fishes, Grech CPF-2500 can be installed. The third day you can notice a few inches down and spot my fishes. Each day it got clearer and clearer and within a week you could see the bottom.

Now your pond will be so clear You can clearly see the snail shells lying on the bottom. Cleaning the filters within, it is a matter of just a few minutes, you can turn the knob to divert the water to your garden and turn the crank handle about 15 to 20 times in one direction,  wait till the water is clear.

Quick read about Fluval Canister Filter

Very happy with this filter!!
The backflushing is very easy; turn the flow control knob to redirect the water inside the filter and turn the crank to agitate the Koi pond pump and filter inside. A couple of minutes of incredibly dirty water outflows to feed our nearby plants. The disassembling & cleaning the filter is a bit tough work to do.

The flat rubber washers are for the smaller adapters and go between the adapter and the filter casing, not the adapter and the screw lock. Also, the flat washers are 2-sided. The indented side goes against the filter and the flat side against the adapter. You can use the 3/4 inch adapter which was a pain to insert in 3/4 inch hose. Submerging the hose end in almost-boiling water was the solution but still difficult.

Based on their instructions, fish load, and the size of the pond, you should buy this model. This one worked like a champ. If you have pond algae problems, get this filter!

Laguna Pressure Flo-Clean 2100 Pressurized Pond Filter


The Click-Fit connectors help make installation quick and easy. The backwash water filter is contained which clears the entire filter, also the foam filters without opening it & can be easily done in a couple of minutes without opening the lid.

This feature gives surety of the filters & also maintains it super go+od. The indicators are provided within the filter to give the signal for the backwash of the koi pond filter at regular time intervals. The Laguna Pressure-Flo Filters are for use in freshwater ponds.

Laguna Pressure-Flo Clean 2100 recommended companion pump. The Laguna filter is one of the best in the business; the design with filter pad scrubbers and click-fit fittings probably make it the best in my opinion.

The only way, however, to have really clean water is to use a UV Koi pond pump and filter. Laguna has a well-designed UV filter also, it is long so that the water will be in contact with the UV light longer which maintains the pond water & does not allow any bacteria or algae to enter it.

The Laguna filter and UV light is a great combination. The only thing I find as a design flaw is on this model is after cleaning the filters and putting the filters back into the bucket, quite often one of the bead balls will get stuck in the plastic tube where the filter holder rod inserts into and stops the lids from closing all the way.

This requires you to pull everything back out and submerging your arm to the bottom of the bucket through all the fishes and move the bead balls out of the way. The plastic tube that these balls get stuck into is about 3-4 inches in diameter and six inches tall.

You can barely squeeze your hand in the tube to remove the balls. My tip on how to avoid this is when putting the filters back into the bucket to lower the Koi pond pump and filter very slowly. If you put it in to fast it makes a current which pushes the bead ball into the tube. Also, be careful to make sure the big ring is properly seated before clamping down the lid.



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