Your Choice For Best Biofilters For Larger Ponds and Serious Koi Keepers

Readers keep asking me about larger ponds and filters to suit so here's my view. Let me focus entirely on larger ponds and larger filters. In particular I will concentrate on high-efficiency pond biofilters ... ie those that perform best in terms of their ability to quickly convert ammonia through the nitrite phase to the relatively harmless nitrate phase (of course nitrate is not harmless and also needs control but it is a minor problem compared to ammonia and nitrite in pond water). The most common of this type are called bubble bead filters or plain bead filter. The best known and well respected are those made by a USA company called G C Tek in Oklahoma state.

Although these pond filters are amongst the best they are unnecessary for the average garden fish pond and should only be considered for medium to large installations and those where the minimum of fuss is required. They work on exactly the same pond filtration principles namely .... When well oxygenated water containing ammonia comes into contact with a surface on which specific nitrifying bacteria are present the ammonia is consumed by the bacteria in the presence of the dissolved oxygen to produce first nitrite chemicals and then nitrate chemicals. The nitrate chemicals are consumed by pond plants as fertilizer.

The fundamental secret to the success of bead filters is that this process occurs in a turbulent oxygen rich environment so that the beneficial bacteria are always exposed to fresh oxygen supply and fresh food (in form of ammonia first and nitrite second dissolved in water) and the nitrates are "washed" away from the bacteria surface to the body of the pond water allowing this "oxidation" process to continue indefinitely ... so long as food AND oxygen are present.

These bacteria need LOTS of oxygen. The bacteria stick to the surface of the beads and do NOT get washed away. In fact beads tend to get stuck together owing to the "stickiness" of the bacteria.

More modern approaches to using an extremely high turbulence approach to biofiltration use a system called The Nexus normally combined with an automatic mechanical cleaning system called The Answer. These systems are excellent but very expensive.

This is what an Aquabead filter looks like and there are numerous models to cope with different pond sizes.

How does the Aquabead manufacturer know how much bio conversion can be accomplished with a bead filter?

University tests have shown that a cubic foot of beads that have 400 - 450 sq. ft. of surface area will handle 50 lbs. of fish being fed 1% body weight per day @ 38% protein. This is the formula that G C Tek use, even though their beads have 500 to 550 sq. ft. of surface area per cu. foot. and in theory should do more. They say they refuse to stretch or make claims beyond what has truly been tested (this presumably implies others might do so BEWARE!).

Bead filters contain beads that ideally should float to prevent loss on backwashing the filter. This is what G C Tek say about their beads called BioGems beads ...

"As you probably already know, if you have done research on bead filters, the beads float. The more buoyancy that the beads have, the better off we are. To increase buoyancy we have added air to each individual bead during manufacture. Why is this important? Because we want the beads to stay as close as possible to the top of the filter during backwash. We want the beads to stay afloat so they stay away from the outlet slots on the bottom laterals so as not to choke off the laterals preventing the debris from leaving the filter. This was never a problem with the old media, but this new design makes for an even better, more buoyant media. Besides the air injection technique, we have Dimpled the surface of the beads, to add more surface and non- abrasion area for the bacteria. This allows for undisturbed colonies of bacteria during backwash, thus creating a bead filter not prone to stumbling after a rigorous backwashing. The size of the bead was slightly downsized, for added surface area, as well. Why go to this much of an effort? Cuz' we want to provide the best filter possible to our customers. We want you happy, not only at the time of purchase, but several years down the road."

Bead filters are cleaned by backwashing and the best models allow air injection directly into the body of the filter chamber to ensure bacteria are kept alive during times when the pond pump may be undergoing maintenance for example. Top models also allow the use of large air flows to break up beads that may have stuck together.

The following are the sizes available in the Aquabead range based upon manufacturer's information ....

The 1.75 cu.ft. is a big workhorse in a small package. The 1.75 cu. ft. model is rated for ponds up to 2500 gals. with flow rates not over 50 gpm for bio-mechanical filtration. The 1.75 can handle fish loads of 87.5 lbs. Comes complete with all 2" threaded fittings for maximum flow and all the "Bells and Whistles" of the larger units. Tank measures 19" X 30". Aquabead pond filters for larger bio filters and koi keepers

The 2.50 cu.ft. is the perfect filter for ponds up to 5000 gal. and fish loads up to 125 lbs. Flow rated at 70 gpm for bio-mechanical filtration. 21" X 34.5" allows you to hide this unit anywhere. Every option is standard equipment. The perfect filter for the majority of ponds. Aquabead pond filters for larger bio filters and koi keepers

This is the 4.25cu.ft. unit. What a nice size filter. A 4.25 cu. ft. capacity designed to be used on ponds up to10,000 gallons with fish loads up to a whopping 225 lbs. That's a lot of fish. Easily flows 90 gpm while only having a footprint of 24" X 35.5". All the extras. Aquabead pond filters for larger bio filters and koi keepers

Now we're starting to talk big here. The 6.0cu.ft. boasts 6 cu. ft. of media and a carrying capacity of 300 lbs of fish. Something for the serious koi keeper. The koi keeper with a pond up to 17,000 gallons with flows up to 120 gpm. All this in a package only 30" X 40". One awesome unit. An unbelievable value. Aquabead pond filters for larger bio filters and koi keepers

This Behemoth will get the job done. An unbelievable 9.0 cu. ft. of beads in a size of only 36" X 45". Remember when bead filters this size stood 10 ft. tall and needed a barn to hide them in? Almost anyone can find a space of 36" to fit one of these monster koi keepers in. Use on ponds up to 25,000 gallons with flow rates up to 180 gpm. Enough said. Aquabead pond filters for larger bio filters and koi keepers