55 gallon, reef, about 60 pounds live rock, HOB refug 3.9gallons, seaclone 100 skimmer, emperor 400. (1inch sand bed in front going uphill to a 3inch sand bed in back). all of my corals have been thriving through this ich, 4 watts p/g T5 ~ my salinity is about 1.024 ~ about 10 nitrates or less, 0 nitrite calcium is about 500, other essential elements are also up fine. Temperature 78-80 (I don't wanna raise it passed 80 because of the corals) Alright, so far I've have 2 heniochus, 1 yellow tang, 4 clownfish and 1 mandarin over the course of the last 2 months die. Like the first month I just had 2 clowns and [2 damsels( that i took back to the store)] and I added the tang, and the heniochus after like a month when my tank cycled. Then my fish got ich, my henichous died, then my tang died, then 2 clownfish died with the mandarin. I had a a firefish and a blenny left ~ and they didn't have ich, they were eating and healthy. I got more live rock and and added the hang on back refug and waited like 2 weeks without buying fish. I got a good deal on a blue hippo tang (small, maybe 2 inches long) and now he has ich pretty bad, and it happened like overnight.. I don't understand why? I don't have a hospital tank and last time I used the 100% veggie formula Ich Attack I feel like it did bad things to my corals. I have the firefish, blenny and the blue tang atm and I don't know how long the blue tang will live if I don't fix something, any suggestions/reasons why Ich is such a problem here?