Feel free to help out or rip a new one

[Dangleflow9]

I have 1 mandarin in a tank with corals and other fish. However, I had a somewhat established pod community before introducing it. One mandarin can usually survive in tanks like this. Your problem is that you are overstocking your tank for the amount of available food you have. It's difficult to get those fish to eat frozen food, so you're depending strictly on a food supply that isn't available.

Your chemical levels are kind of high. You need to bring them down. Do water changes as others have specified. To help combat this issue, I would recommend drastically increasing your clean up crew. The amount of snails and hermit crabs you have are much to low for that size tank.

 

[frogdog]

I can't answer that about the furan. You would have to ask that in the fish disease/treatment forum. I'm not sure why you want to dose with furan. but like Dangleflow9 said, first get your water quality under control.

 

[mmeadows]

RIP male mandarin

 

[frogdog]

Well, you asked for help and are trying to make things better. Give yourself credit for that. You still have a whole tank of critters that need you. RIP little fish.