Give them alot of hiding spots large enough. For the salts question I have dosed the tanks with those guys in it with salts and they did fine with it seemed much happier though I only did this for a very short time. I have 2 11'' ones and 2 6''+ (ones a spotted though) then I reduced the doseage after a month.
from my experience. do a setup with NO sharp edges. They're very clumsy when they get bigger and would cut their fins and wear it down to the nub. I'm trying to avoid that right now on those setups when they're trying to squeeze their fat selves in holes. I have a 6'' PVC T connectors in the tank and the edges of that PVC connector is not that sharp. Though they do hang out in those they like to hang out in smallest pVc pipes they can squeeze themselves into like a security blanket.
from my experience. do a setup with NO sharp edges. They're very clumsy when they get bigger and would cut their fins and wear it down to the nub. I'm trying to avoid that right now on those setups when they're trying to squeeze their fat selves in holes. I have a 6'' PVC T connectors in the tank and the edges of that PVC connector is not that sharp. Though they do hang out in those they like to hang out in smallest pVc pipes they can squeeze themselves into like a security blanket.