Travis the largest ones are about 3 1/2 inches and I feed them Krill, Salmon, and ground up Aquamax 600.
I'm using a Marineland dual wheel bio filter and a Tetra filter on the 40 gal. tank and the water quality is fine.
About 2 weeks ago I lost one of the big females in the 100 gal. RAS, it's the only loss I've had in the 2 winters it's been operating. She looked fine so I don't know if it was old age, or something else, no other problems.
Have you had any luck in finding suitable property to put your ponds on?