: Do what your lfs
said.. Watch closely.. 1 grain does not an ich make.
While you're watching get a QT setup. It doesn't have to be a full blown tank. Get a small 15g tote or anything and start cycling it. Use your existing tank water from a water change. If you can't get filter media you night need to part with a small piece of your LR
to get some bacteria in there (the LR
will be trash after treating w/ copper).
Again, that's an emergency situation.. Long term you need to get yourself a small tank, small filter, small powerhead,etc etc.. Not having one will only cause problems down the road. As you may have already seen from not QT'ing the puffer.
Your options with ich are limited. Your options with ich and inverts/corals in the main are even less.
Your question was answered just not in the way you like. If it is ich something has to give.. Treat the main and probably/possibly lose everything but the fish. Treat in a QT and save the inverts/LR
, save the fish (hopefully) and get that elusive QT (and your fish will have to stay in the QT for xx weeks ..I forget.. check the links..6 weeks?)