sps issues

[jfuka78]

To start I had an Alk swing a week or two ago. Got up to 15, wince then have been pretty stable.
Sps is bleaching very bad starting at bases.I have lost over half my sps. Lps and softies are great.

Alk 10
Salinity 1.026
Trates undetectable
Phos says 0 but I have bad cyanobacteria
Mag 1400
I recently hooked my skimmer to bring in air from outside of my house. I heard this would be good because closed up houses have a lot of co2 which helps in aiding cyano.
Just did a 80 gallon water change the other day and swapped media in reactor and noticed that all my gfo some how got into my tank when I looked in my sump and skimmer. I am guessing the gfo burned them but not sure.

Please help

 

[jfuka78]

Some of the devastation

 

[MHG]

That's not bleaching that is tissue necrosis (STN,RTN).... Get that alk below 9. With no nitrates that happens every time in my tanks... I stopped running with zero nitrates because it is way too stressful keeping the alk below 9 (8 is better)... With any detectable nitrates you can let it swing up. Down is still bad......

 

[deepseadan]

I have been experimenting recently with alk and how it affects sps. I usually run between 7 and 8, but I wanted to see if I could get in the 9 range so I wouldn't have to stress about it dropping to low. So I turned up my brs alk doser and very slowly (over weeks) raised my alk to 9 and almost all my sps lost color. I slowly brought it back to 7.5 and everything regained color again. Not sure why, but my sps don't like a dkh above 8. There is a very strong relationship between alk and sps color. When in doubt as to why your sps are having color or stress issues, first check you alk and if necessary adjust to 7-8. That may be the fix.

 

[jfuka78]

I always ran mine at 10 before with no issues, but will try anything now. I shut my controller off to lower Alk. Will check tomorrow to see where it is.

Thank you for quick responses.

 

[rogerwilco357]

and your sure you have no pest like aefw in the tank. I use to have my water at 10dkh 450 cal,ph at 8.10 and mag at 1350 my sps loved it..only till i got hit with the aefw and it wiped my sps out over the year...thats why i ask