New setup (old tank)-Hippo with Ich

[shooterg22]

I purchased a 150 gallon reef tank and got it set up about 2 weeks ago. This tank was moved by a "professional" and was about 1 hour from my house. Everything seems to be running well now and the mushrooms and leathers are looking better than they did at the previous owner's house. The salinity was a little low (1.019) when the lady set up the tank but when we filled the sump and started it last weekend (it was down for about 1 week because they broke the prefilter/overflow and I had to fix it) we brought the salinity back up to 1.021. During this time, I left her HOT filter running and cleaned it everyday (it's now in the garbage).
I noticed yesterday that the large Hippo Tang is now getting Ich spots on his body. These are the same fish that were in the tank before and all I have added are a few snails, hermits and pep. shrimp (no cleaners in her tank at all). I did not put the LFS water in my tank. I do not have a qt tank...what do I do? I read the articles on hyposalinity in a qt tank. Should I buy a tank and pull the Hippo (he's about 5"-what size tank do I need)? I also have a yellow tang, a mimic tang, a clown and a dumb damsel. They do not show signs yet...
Thanks!!