DonnoBBD, The best cheap media that I've found is nylon baler twine. You can pickup a 20,000 ft spool at TSC for about 20 bucks. Take a long serrated knife and saw thru the spool lengthwise and you end up with a whole lot of short pieces. Fill up a barrel or IBC with it and you've got a very good bio filter. The black boxes are very pricey but being gone all week forces them. The big trick is getting the solids out early before they dissolve. I never had much luck with a swirl filter but the best thing I used before the RDF was a sieve. It had a 300 micron screen and was really very effective. There's a guy on youtube that goes by mrsuperb1 that has some pretty good vidoes on building one if you don't want to spend the cash to buy one. The main piece of advice I can give if you just want a FUN father son project would be to keep the stocking density LOW. 25 fish in a 275 gallon tank is FUN. Above that it becomes WORK. Above 50 becomes a full time job, HA Good Luck, Steve.
Watched your videos over and over trying to figure out the flow. It appears to me that you just run a pile of air to keep the water in the take moving so much that the particles end up going out the skimmers. High amount of air makes the waste partials light.
Do you stop the pumps to feed? How do you keep the feed from just shooting out the skimmers? Sinking feed high fat?
What my son and I see doing is to raise some of our perch that we trap out of our pond. Some young perch that are hatched in the pond but can over populate the pond quickly. Just wondering how many perch would equal one tilapia for your 25 fish per tank calculation. My son is so excited its not funny.
Cheers Don.
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