[Funky_Fish14]

Jason I think his tang is dead, so he cant exactly have an issue with it anymore?

Any fish poking their head out of the water often means either not enough oxygen, or too much ammonia in the water. But given that you had just done a 25% water change (good idea btw), then I think maybe he was just stressed out? I would leave the powerhead there for now. I really dont think your fish died as a result of an oxygen problem. How big was the tang though? I mean unless it was huge and the clownfish are very big, its quite unlikely. It really doesn't take much to oxygenate the water, and HOB filters do a great job of it.

Also, a salinity level of 1.023 is not bad at all, just a bit low of the normal range. This probably would not cause your problem either. A refractometer is definitely a good investment (as you had mentioned you were considering).

Can you better describe the 'shedding' that your fish seemed to be doing? Was it slimy? Coloured? Rough? Clear? Thick? Did it peel off easily? How quickly did it form/come off? The more the better.

Good luck with the clown!

Cheers,

Chris

P.S. - I would take up the other reefers on their offers to come by and check out the tank. Sometimes an in-person view helps, and also they could bring their own testing kits and double check the measurements. The more confirmation and the more eyes, the better.