Qt my yellow tang for a little over a week now. Read up on Humblefish's and Hotrocks guides and so far it's going well. My tang is in a 20l, hob with martrix media, wave maker, air stone, and seachem ammonia badge. I'm using copper power and Hanna checker and finally raised copper power to 2.50ppm. Question is, if the ammonia badge indicates green, do I do a water change? I have m7 and prime on hand, should start using that? Therapeutic levels, is there a minimum with copper power? I don't want to do too much of a water change and restart the clock. TIA guys and gals!