I think your pump is oversized for the needs of the system biofilter. Evidently my post about pump size (gpm) did not get posted in this thread due to website technical problems. I proposed the rated flow volume of the pump should be in the neighborhood of 7 to 10 gpm which would also allow for a pump head height of 5-6 ft. IMO actual flow to the biofilter only needs to be 4-6 gpm (max 10-20gpm). Significantly higher flow rates could possibly actually decrease efficiency of the biofoilter, although I am not an expert in this.
Can I ask who recommended the pump size or how you determined size of the pump you are now using? Does it have a flow rate that you can provide? A pump requiring a 1.5" dia pipe seems like way too much flow for a 55 gal trickling filter and a 600 gal combined culture tank containing 20-30 fish (6"-10").
When I had a simple trickling filter made from a 5 gallon bucket, I had the water discharging through a hole in the cover/lid (prevent external splashing) into the center of the biofilter. Then the flow hit a flat large dia inverted lid with a 1/2"-1" rim to help contain the water until it drained through onto the filter pads. The lid had lots of small (1/4") holes randomly placed in it. In the lid/spreader I placed numerous rocks to help redirect, slow and spread the flowing water from the discharge pipe. Water moved through the filter pads, trickled down into the biofilter media and collected at the bottom of the bucket where it flowed by gravity out onto and powering (waterwheel) a rotating drum biofilter that sat in the fish tank. Filter pads were rinsed and cleaned once/wk or overy other week depending on how much solid waste was being produced.
Last edited by Bill Cody; 01/16/08 08:27 PM.
