Thanks for that info badflash, I'm working on a bio-filter for my setup to see if I can't improve on the growth and budding of the plants (I'm not sure it will help, but it surely couldn't hurt )

I have a question about the calculations ......

1. Fish size & species ...... you might have two 1 1/2 pound Tilapia (3 lbs) that you're using for figuring, where I've got maybe 100 feeder Guppies (1/2 lb?) ...... your Tilapia process the food at a much higher rate (1.2:1) than Guppies which probably don't have a ratio listed that we can use for a figure ......... so even though you have more poundage of fish, I'd venture to say that my fish would put out more ammonia/waste than yours. Is my thinking on this correct, or am I all wet?

It doesn't have to be Guppies, it could be catfish, Bluegill, Crappie, Bass etc. they all convert the food at different rates, so wouldn't that make a difference in the calculations?
(i.e.TILAPIA convert food at around a 1.2 to 1 ratio, Meaning for every 1.2 pounds of food they eat, they will grow 1 pound. Catfish and Bluegill ratios are around 4 to 1, Crappie 6 to 1, and Bass are slow at around 10 to 1.)

I just wanted to clear up this question before I finalize my figures for the filter I'm making . THX