Quarantine Tank

[Pat-O]

So we just randomly lost our Kole tang its been doing great swimming around everywhere picking at everything and excepting a wide variety of foods and we came home to our neon blue reef hermit eating it. We tested water levels everything was good a couple days before and even ok after it died. My first guess/worry was ich. We thought we might have saw a couple little white spots on it and it was always trying to get cleaned by my cleaner shrimp. Now my clown is acting completely normal but I think the ends of its fins look kind of fuzzy. So my plan is to set up a qt tank I have a lot of tanks sitting around from my african cichlid days. Im wondering If i fill with ro di salt water and throw a piece of live rock in with a hob filter i have sitting around will it be ok or do i have to wait for it to cycle and have a lot of other equipment.Also do you guys think it sounds like ich or possibly something else.

Any info and opinions would be great. The tanks I have lying around are a 35,55,30,20, and a 10gal.

[larryandlaura]

I use tank water from a water change in my QT tank with a hob filter and a small powerhead nothing fancy for a 29sump gallon standard with some ofc for them to hide in. It has always worked for me.

[Pat-O]

Plan to start setting it up asap and finishing in the next week or two. I have a decent amount of equipment. Do i need anything above a basic aquarium light for lighting? How serious should a qt tank cycle before its used?