Well, I have a pajama cardinal fish and noticed that around it's mouth it is turning black. I found a picture on the internet that looked just like how the fish looks. It was talking about how the dark spot is a sign of stress and is called melanosis. I wasn't sure if there are things you can do to help with the stress, garlic, keeping lights off, things like that. I am also wondering if it usually leads to death.
This tank has quite a history. I've had it for three years. I had to move it from Indiana to Colorado. All of my rock died in the process. I set it back up, cycled it again and eventually added two clownfish that died after 3 or 4 days. Then, the job that brought us there fell through and we moved back to Indiana. I had all of the rocks stored in saltwater for 4 months while we found a place to live. Then, I set the tank back up. I bought three new pieces of live rock and put all of my base rock in there too, after scrubbing and rinsing them thoroughly. I then cycled the tank again and added my cleanup crew, which are still in there and alive. I then bought two clownfish a couple of weeks later and they both died after 4 days. So, I didn't buy anything else for 3 months, thinking that if there was a disease in there, it would be long gone since then. I just bought my two pajama cardinals (bought them because they were cheap, just in case I lost them) and two more emerald crabs. After drip acclimating them, and two days, they are both showing signs of stress.
I have no idea what could be wrong with my tank. I am able to keep my shrimps, snails, and crabs alive with no problem. My parameters in this 55 gallon are
ammonia 0
nitrite 0
nitrates 15
ph8.2
temp 80-81
I have a wet/dry, skimmer, two powerheads, about 120 pounds live rock, with 100 of it being base, but slowly becoming live again, and I have a 2-3 inch live sand bed, which was also stored in saltwater for all of those months.
Beth, honestly, any ideas you have would be so great because my husband is about to the point where he is going to make me stop wasting money on fish. At that point, I'll only be able to buy some corals and keep my cleanup crew. Well, I have two little ones who really don't care about that stuff and are really excited about the fish. I really want this tank to be successful like the first time I ever set it up.