3 a week, I drain 35-40% at a time then fill and drain at the same time until the tanks 65% full then I take the siphon out and just fill it up. Dang crowded tank. Im doing one as we speak.
i dunno yet.. i just added another thank and moved a bunch of fish around... im not really sure how this is going to go yet... so for now im doing daily water tests and just sorta winging it