Take serious note on what 'xmetalfan99' have been saying. It is true for most LFS worldwide, the level of prefessionalism they possess is critical but the cruel facts are mainly on the collection, holding and transportation processes. Aside from the improper chemicals being used, nowadays, especially small scale collectors, the animals have never been properly handeled and quarantine and most lekely shipped the same day after the caught and the main distributors just shipped them out overseas just after taking out the dead ones and may be repacking them to save on air bill. That happen worldwide, some stocks from Hawaii suffered the same about 6 months ago, but the situation has improved since. You can be more distressed if you know the level of casualty the retailers might encountered from time to time. The infected/stressed animals can look and react normal during the first or second week after they arrived at the retailers or the consumers, they even eat and swim properly. Things then changed and the poor fish eventually died within a couple of days. So if you are not sure or not keen enough about what you are buying, go for captive breed or simply get one captive instead of 4 to 5 wild caught from a reliable retailer. Back to your tank, is there a skimmer included in your setup. It is a vital equipment, unless you are very, very experienced. Apart from that, the PROPER use of high quality carbon seems a good and worthwhile addition to your present condition, no more additives from now on. I also noticed that you seem to be using crashed coral in your filtration, you can consider to change them to good quality bio rings, which can more effective and less potential hazards.