some good..some bad

Ok iv got quite a few mixed corals and some are doing great but others are not. I have just lost a brain and a torch where my hammer and zoos are really strong?? Waters are spot on apart from calcium which was 350..dosing now.
The only thing I can think of is temp..its at 28 always even after unplugging heater?? Is temp that much if an issue??
Acans is fading now too and it was one of my strongest

 

Some corals are hardier than others. Yes temp is very important.
Are you having a big temp swing?
Most coral cannot handle a big swing in temp.

 

That would be 78.8 F, the corals should be fine with that temp. Loss of LPS is often due to swings in Alk values. Do you have current ALk and Magnesium values?

 

Alk was low too when I got red sea test kit along with ca..so started dosing both but Im doing it with bottled mixes and adding quarter litre every morning trying not to spike. Iv found alk and ca kind of alter each other and im fighting a lost battle. Will do fresh tests tomorrow after water change and post back.
I havnt got a sump or auto top up etc so its pretty laborious

 

Yes temp swing from 2 t8s and 2 t5s is quite bad. I have unplugged heater at the mo to cool off. Led needed maybe?

 

Actually 28° C = 82.4° F, which is a certainly warmer than I like to keep my tanks (I prefer 25° C, 77° F). But consistency is the key either way. Does your temp swing at all, or stay at 25° C?

 

A member on here suggested my leather may be doing chemical warfare. I took it out a few days ago..water change..fresh carbon and already there is massive improvement. I wish I joined this forum months ago