I’m having an issue. So, about 2.5 weeks ago I bought a new fish a small clown tang to put in my 65 gallon reef tank. In it was a tribal blenny, clown fish, blue tang, 3 chromis and fairy wrasse. So the clown tang was doing fine he was eating and swimming but noticed ich pop up tried lowering the salinity for .25 to .22. Didn’t work he died and then my blue tang caught it and he died about a week apart. I was like okay maybe it’s over I know tangs are prone to parasites. Then my clown fish caught it which really surprised me and he died a few days later. Now it had a short break between the tang and clown. This happened in the past week. Simply put all of my fish are dwindling away one by one about 3-4 days apart. After the clown the wrasse died. I thought it was the end. I talked to my lfs and my tank is by a window so he told me to put insulation around it so I did to help keep temp under controls. Thought a lot of this was happening from bad temp swings. Made sense to me. I’ve got my water tested at the lfs and he never gave me numbers just trusted him. He would say your water is dirty do a water change so I would and it would be good. I do a water change of 15 gallons every week now and that keeps my water clean from what he says. So needless to say idk numbers. Today my blenny died which really shocked me since I saw no signs. Just seems he dropped dead all of a sudden. Now I’m coming here to see what people think. To add with temp swings I know I was running on the warmer side so I bought a temp controller to help keep the heater from over doing it. So I hooked a fan up to blow over the water when the lights are on to keep the water cooler and it has worked. Idk what to do honestly.