I got hold of tanks about 34x40 in in area. Will hold about 275 gal to use for sand filter. I want to bring water in the top and run a 2 in down one side with 5 11/2" lines across the tank for air with a 2" header and 4 1 1/2" laterals for water fed from the opposite side of tank. I was wondering if I need to separate the pipes with a grate or if filling the bottom of tank with 1 to 2 in rock would be good enough?I would have air on both sides of tank and between each water line.
I am not interested in getting biological action but want to remove the fines so i would be guessing as to depth of various layers of rock. This is my first try on a forum, so please excuse my feeble attempt.