I've done TTM on 3 fish now. I prefer it over copper. Copper and worrying about its perfect levels, not too high, not too low, stressed me out far more than having to make water and dump the tubs every couple days. I just use 2 plastic 16 gallon tubs, and put 10 gallons worth of water in them with a heater, air stone, and 2 pieces of pvc. I do mine in the basement on the concrete floor so its as easy as dumping the tub down the floor drain and laying the equipment out to dry. I haven't had any detectable ammonia levels raise up, but i've only done it with small fish. For larger fish it might be more of a problem. On my most recent fish, I dosed API General Cure instead of Prazi on the last night before transfers 2 and 4. And I have a fully cycled 30 gallon QT for them to hang out in for a couple weeks after TTM is over before moving to the DT.