keane
Fish Herder
I have never worried about anything more than salt, temp, and hidding places. The salt question is a good one, my whole tank did better when I added a little salt, just read the package it will tell you how much to add.
Clown loaches are scaleless fish and should not, under any circumstances, be subjected to salt in their tank.
It will burn and cause far more damage than good.
The same applies to corydoras and any other scaleless fish.
steve