Make Your Own Garden Pond Biofilter ... Summary

• There is no fixed shape, size, location or anything else for a biofilter.

• Any biofilter is just a place where water, fish waste and oxygen all of which are dissolved in the circulating pond water can meet the bacteria responsible for converting this waste (the waste is actually food for the bacteria) into non toxic chemicals that remain dissolved in the water.

• The more oxygen in the pond water the better because then the pond filter bacteria are lively, strong and hungry.

• It is easier to get a good spread of oxygenated water across the biomedia by allowing water to flow up through the pond filter biomedia

• Brushes are used for solids removal in a bio filter and are installed before water reaches the biomedia bed where bacteria live.

• You can substitute brushes with almost anything to do this job so long as you do not restrict water flow through the pond filter.

• A common substitute for brushes is open cell foam. Foam at the top of this pond filter creates mechanical filtering capability as well as some extra biomedia capacity because bacteria can live satisfactorily the tiny holes (open cells) within the foam.

• Make sure you keep a space at the bottom of the pond bio filter for solids accumulation and install an outlet including valve so that you can drain and flush out this bottom compartment easily and quickly (use a bucket of pond water and pour down through filter bed with the drain valve open.

• If you let solids build up in the base of the pond filter you will create a breeding ground for pathogenic bacteria to accumulate and you will run the risk of serious fish disease .

• Place biomedia on a conveniently handled perforated plastic tray (like one of those bread crates you see in supermarkets). In addition place the biomedia in a string bag of some kind so that the biomedia can be easily removed for rinsing.

• It is important that the pump runs all day every day so get a good reliable low running cost pond pump here.

• The more pond filter surface area that can be incorporated into the filter box the better.