My 150 gallon circular fish tank in the basement uses a sieve screen mounted in a plastic tote, two sock filters, and an up flow sand filter for mechanical filtration. Biofiltration is two 55 gallon blue drums with plastic media that mix constantly via an 80 lpm air pump that also supplies air to the fish tank. A 1/2 hp chiller fed with a 10 gpm mag drive water pump keeps the water temp cold enough which can be digitally set. The entire system's water moves by gravity and a 15 gpm mag drive pump.
This is my second year hatching trout eggs in floating laundry baskets. As you can see by the picture the laundry baskets have the bottom and sides cut out and nylon screen siliconed in.
Some hatched fry in one of the baskets. For some reason the photo makes it seem like much less than there are.