Hey everyone,

can someone please point me to some great box filter designs? or contribute some advice to my situation.

my pond is approximately 3000L (about 900 gallons) with a 7000L/ph pump. There is already a rectangular box plumbed in and i would like to save the hassle of starting from scratch if i can help it.

The box is divided into halves separated (down the width of the box) by jap mat with bags of rainbow quartz, shell grit and bio balls covering the water inlet providing the physical filtration in one half and the filtered water occupying the forward half.

my currents concerns are:
1 - my filter media fills up with pond muck very quickly and i am having to clean it out at least weekly (pond floor pretty much needs a good vacuum)
2 - i pack the media bags fairly tight to maximise my physical filtration but this impedes my water flow. Where is the line between filtration and water flow?
3 - would i gain increased filtration and flow if i moved my material to the bottom half of the box rather than the forward half??

thanks for your help and time.