rkelman, the other day I noticed that several of my oldest ocellaris juveniles (almost 3 months old) had flared gills. This was a couple of days after I changed their water - I usually pick up 5 gallon buckets of RO/DI SW from the LFS for the babies. I read back through all of your posts, but couldn't find what you used, so I picked up some Triple Sulfa since it said it treated flared gills. I used one pkt, as it recommended, for the 10 gallon tank. The next day, 15 of the 18 were dead. Maybe I should have done half-strength for juveniles?? This was heart-breaking because these were my oldest babies and they had been so healthy! I took the remaining 3 out and put them in new SW without the medicine and just an airstone. Only one has made it as of today. His gills are still somewhat flared, but he's swimming around and eating. Their tank was fully cycled (hydro sponge filter) with 0 ammonia and 0 nitrite. I looked at one of the last ones that died under a microscope, but I didn't see anything on his gills (I was looking for parasites), other than they were somewhat red. My microscope wasn't strong enough to see any bacteria in the water. Do you think the water from the LFS could have caused this? Do you (and anyone else) have any recommendations for how to treat the survivor? I have four other tanks of younger babies. I definitely want to be prepared should this happen again. ANY advice would be greatly appreciated!