Aro is a ~20cm silver (yes, juvenile). She seems to be growing alright, but it's an office tank & I'm feeling like she's not keeping belly-weight even with every-second-day feeding. Really need to find a better roach/bug supply...
The risk to be minimized was not introducing novel fish (feed) variable. Tank is my 6'x2'x15" 100 that's only been back up&running for a week, but its filtering through a 2gal pond canister that's been running for 3months. Substrate is the 3year old oats sand from the previous set-up of this same tank and has never been dry. BB, MTS, pond snail, tubifex(?), ostracod etc. established, plus plants. I am a little worried that the pump moving water through the filter is a little weak, but I've set a wave-maker for current/motion incl. over the sand. The wave-maker's making a proper racket, though... something's amiss.
And yes, the 100 is being rapidly outgrown. Her 250gal will be ready in Feb.