Rtn?

Well all speculation is worthless until you get a true ALK value.

It does look like Alk burns to me as well.

If you are running any type of carbon you may need to keep your alk at a lower value to avoid alk burns. Are you dosing anything?

 

Looks like I'm picking up a alk kit this weekend.
I don't dose anything. Usually water changes keep most levels in check.

Although I have to admit I have been a bit lazy in the testing department lately but who can say that hasn't happened before

This sps is one of the 3 I have and the rest of the tank is lps/nems/softies and they seem to be doing great. I will have to get on this asap though.

 

Its hard to just size or distance in the pick but how far is that Lps to the right and which way is the water moving through there? I don't have the much experience with lps but did have a coral similar to that that had very long sweeper tentacles.

Also I'm not saying don't get a test kit but if you aren't dosing and only doing water changes and didn't get a bad batch of salt I would find it hard to believe its alk burn. But if you are looking at keeping sps alk is probably one of the most important things to test.

 

It's obviously not RTN as the "rapid" part is not happening. I to believe it has to do with an imbalance of ALK, CA and PH

J