3 out of seven fish dead since disease arrived. Any suggestions will help

[tjohnso]

about 3 weeks ago I noticed my pink tail trigger had what I thought was ick. I began treating the tank with rid ich and daily h20 changes. I than increased the temp to 82 degrees over a couple days. Soon after my blue hippo had a white coloration over its skin. a day or so later I came home and discovered my lionfish had been eaten or died and was eaten not sure what happened. The next day my wrasse and puffer began acting stressed. gasping for air, lethargic, barely moving. I than lowered the temp back down to 78 where it was before. The wrasse and puffer continued to not eat and barely move for 2-3 days. I than set up an emergency qt tank and put wrasse + puffer into. The strange thing is the wrasse showed no signs of skin irritation or strange coloration. The puffer did have a blackish brown spot near his top fin. 2 days or so after being put in qt the wrasse died. Puffer continues to not eat and is swimming upside down has a hard time leveling out. Now today after having ick for a couple weeks the blue hippo out of the blue began sitting face down into the sand and gasping for air. I did initiate hyposalinity about 3 days ago not sure if hypo stressed the blue hippo out or not. So tonight I put the blue hippo in my qt tank with the puffer who is still trucking but still not eating and the hippo died in 1 hour. The temp and salinity are the same my only guess is it stressed him out or maybe its b/c the tank hasn't had a chance to establish itself in the short time I have had it. anyways now Im down to my pink t trigger, clown trigg, and blonde naso tang who are all acting normal for now. pink trigger is only one out of the 3 that has visible white spots. Are these fish just hardier than the others?
I will continue hypo at .009 for now. Im bringing my water in for testing tomorrow.
Does anyone recomend a uv sterilizer? I am thinking of buying one tomorrow.
Any insight will help. Thanks

 

[1911_guy]

Your QT is not cycled.

 

[david24]

I would recommend a UV sterilizer whole heartedly.
I have a coral life UV sterilizer that I count as my most important purchase. It not only helps a lot with disceases but makes my water so clear it looks like my fish are swimming in air. Which before I installed it my water was very cloudy.

 

[tjohnso]

Well, I figured out that my protein skimmer was submerged too far in the sump so the pump did not have enough power to run the skimmer properly. I used a coffee cup to move skimmer out of the water and within 48 hours my sick puffer who was on the verge of death got better. He hadn't eaten in 1-2 weeks now he's scarfing everything in sight. I also purchased a uv sterilizer which has cleared my tank up quite a bit and algae groth seems to be going down. Thanks for the advice. I have learned a lot from this experience.