Pond Bead Filters

A bead filter holds a bed of small floating plastic beads. Water pushed through that bed leaves its solids behind, and the same beads carry the bacteria that convert ammonia and nitrite. Mechanical and biological filtration happen in one vessel, which is why bead filters suit koi ponds, where the fish load is heavy and the water has to stay genuinely clear rather than merely green free.

Size it by pond volume first, then by fish load. A koi pond wants a filter rated well above its gallons, because fish produce far more waste than a lightly planted water garden of the same size. Check the filter's rated flow against your pump: too much flow pushes waste straight through the bed, too little lets it pack down and go anaerobic.

Then decide where it sits. A pressurised unit runs sealed under pump pressure, so it can stand above the water line and still push water on to a waterfall, which gives you freedom in the plumbing. Low head models are made for pumps that cannot fight much resistance. Complete systems arrive plumbed as a package. Cleaning means backwashing rather than pulling out media, and our guide to pond filter cleaning walks through it. Match the unit to your pond pump.