So, my ~56g needs to be stocked

What about-
1 Red Tailed Shark
5 Barbs
6 Oto's

Tank is WELL filtered.
Fluval 305 Canister (I think it's a 305)
also a hang on tank biowheel.
 
6"-12" is a huge range, I also don't think 12" is right. I know severums can go in a 55 gallon and it's only 13" deep. I've heard 8" but I've never kept one so maybe someone else can chime in. Anyway a single one would be great with that combo IMO.
 
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