A lot of times growout tanks have inadequate filtration and little guys stress easy. We all like to power feed the growouts and the water quality goes to pot. My 55g growout tank had a 35g trash can filter with bead media and japanese filter mat for bio along with a sock for mech. I never gravel vac or touch the tank. It had a 900gph Quiet One pump. High turn over rate and cleaning the sock frequently worked for me. 30% WC once a week. Twice a week as they get bigger. Pellets only helps filtration. You need to borrow my parrots.
PS..the glass filter on my 240g incorporates all the above (high flow and purging of bio waste frequently without stress on the fish. I am not trying to sell glass filters so don't get me wrong. Just trying to share the concept.
Think of the Ultima and glass filter as a giant canister filter. Not a sump.