Hi I have a 40 gallon qt tank I just got I need to treat my 6 fish for ich being 3 clownfish, 1 tomini tang, 1 blotched anthias, and 1 BLUE STAR LEOPARD WRASSE. What copper should I use to treat them and for how long of a copper treatment. I’m leaving my DT for about 78 days fishless. Also do I need to buy a copper test kit?