Good looking tanks

If you're worried about the possibility of ICH, you could run your tank temp on the high side. It's generally a good thing to do anyway for any inflictions in general. What temp do you run already? If not up there I'd suggest winding up to 82-84f for the convict. If your down around 78f at the moment perhaps only adjust heater 2 degrees at a time and wait a while in between to avoid too sudden of a temp swing. ICH doesn't do well above 80f.