I am making an U/G filter out of corrugated plastic roofing covering 95% of the base of a 4ft by 18 by 18 inch aquarium
Sheet available from bunnings for around 10 bucks
The ends of the corrugation will be sealed with PVC sheet,and sylastic, and it is held off the base by 1/4 inch spacers
The Outlet will be only one tube at the centre rear and connected to my 1400 l/hr external filter
Slots will be cut in the valleys of the sheet with less nearer the outlet and more toward the ends to balance resistance and subsequent flow. Plants that love this set up are well rooted such and Valisinaria, indian fern, amazon sword etc
Gravel will be Waituna lagoon fruit salad type
Will post some pics when complete
