tank issues

I recently upgraded from a 90 gallon to a rr 125 gallon (a month ago), used all the water and live rock from the 90. Had a RENA XP4 canister filter and dual BAK-PAK skimmer, (both for sale btw!) I now have a reef octopus sump and skimmer (HUGE difference in the skimmer!) My uncle, Big John, helped me set it up and plumb everything. Everything looked great until 3 days ago, ICH started showing up on my tangs. I lost 3 royal grammas, flame angel, and this morning my powder blue died. I had two visi-therm heaters in the tank. they both had moisture inside them. Took them out and threw them away. I'm thinking they may have been releasing voltage in the tank causing stress to the fish. I bought 2 200w jager heaters last night from Andrew at Anemones, Clowns, and Corals. Andrew and Craig have been a HUGE help!! They let me bring 3 other tangs to the store to be treated, and they are showing signs of improvement! I'm hoping that the heaters were my problem! Time will tell!