2 dead fish?

Our tank has been up and running for almost a year. We've got several corals (frogspawn, candycane, golden torch, mushrooms, zoas, xenia, and an acro) and we had 6 fish (2 clowns, melanarus wrasse, black cap baslet, starry blenny, and a potters angel). The potters angel we just added into the tank 2 weeks ago. All of the other fish have been in there for a long time.


Our water is testing out fine both here at home and at the 2 stores around here. We've been having problems with our zoas dying, and also our mushrooms used to open up huge, and now they're shriveling up and don't open that big.


Our lights came on today and my husband noticed the blenny was dead on the bottom. He then looked further in, and the potters angel was also dead.


We just had our water tested yesterday, and it was ok. The pH was a little low, so we added buffer for that, and also added a magnesium buffer.


The blenny was moving around last night, as was the potters. My husband said he saw the potters moving around earlier this morning. Neither showed any signs of being sick or anything. The last few days, the potters has been hanging out up near the overflow box and not moving around a whole lot, so I wasn't sure he was going to make it anyway.


Both stores around here are closed today, so we don't have that resource to call and ask questions. Does anyone have any insight as to why our fish have died (or our zoas/mushrooms are dying)?

 

Nope. No other changes. The only changes we've made lately is adding the potters angel and then dosing for magnesium, which we've never done before. Joe told us to dose a teaspoon of the magnesium once a week. Thats the only thing we've done differently.