I found a scrubbie supplier and was wondering if there were any rules of thumb for how many ft2 of biofiltration surface area you'd suggest for raising relatively low intensity fish (probably catfish, perch or bluegill or ....)

Per a website I found, scrubbies have an area of about 370 ft2/ft3 of material. My tank is about 1500 gallons and if I stock to end up with adult fish at a density of 1/2 lb per cubic foot (or about 1/15 lb per gallon) for a total of about 100 lb of adult fish to harvest, is there any rule of thumb to suggest how much surface area I need?

I have two ways I can go but sort of prefer the idea of choice 1 below:

1- I got an old hot tub pump with a high and low speed from my brother. The low speed uses about 300 watts of power and I was thinking it would be nice to just run that pump at about 2000 and wash the flow down over the scrubbies (maybe 4 ft3 of them?). I would make a distributor pan with holes in it to run down on the top of the scrubbies and make the bed of scrubbies 1 foot deep. It would be suspended above the tank and drain down into the tank. I was thinking about putting a box above the biofilter filled with shredded corrugated cardboard and use that as a filter for a slip-stream of the flow (most would go through the biofilter but some would go through the cardboard filter). I was thinking of putting red worms in the cardboard and letting them live off the fish waste and filter the water at the same time.

2- I also got a blower with the pump which was also from the hot tub. It blows a ridiculous amount of air and makes a huge geyser. It is also loud. Do you think I need the more air than I will get with the system of spraying down over the box of scrubbies? If so, I can set this up like the aquacube and submerge my scrubbie collection, maybe in a nominally 18" diameter piece of plastic drain pipe and blow a bunch of air in from the bottom. The only thing I don't like about this idea is that the blower is loud and may pull more power than the pump (not sure about that because there is no nameplate data on the blower).

Any thoughts about the pros and cons and if the pump and biofilter would be sufficient for oxygenating the water for 100 lbs of fish. By the way, I know it also matters how much I feed them each day as well.

Thanks,
Wes