Sps bleaching , alk raising …

[Rmckoy]

Curious why . Or if someone can answer a few questions how this is ….

noticed the few
Sps I added awhile ago have started to bleach from
The top . And within a day they’re completely white .

tested water but nothing jumps out at me other than curious why alk is higher …,,,

I have noticed a fair amount of cyano on the bottom ,

we’re in Canada and recently had a some extreme cold .
the dt is close to a door so maybe temp drop ?

current levels
Sg : 1.025 Hanna
Temp : 74.6°f
Alk : 8.12 ( 145 ppm ) Hanna
Nitrates 5ppm salifert
Phosphorus 39ppmb = 0.120ppm phosphates

previous levels
All the same other then
Temp : 79°
And alk 7.5

 

[cmaxwell39]

How long has the tank been running at the lower temp and how quickly did the Alk rise?

Either of those changes could possibly cause problems with SPS depending on the speed/duration of the change.

 

[Rmckoy]

How long has the tank been running at the lower temp and how quickly did the Alk rise?

Either of those changes could possibly cause problems with SPS depending on the speed/duration of the change.

Alk has been 7.5 for over a year .
temp ….. dropped in the last few days .

alk was 7.2 dkh last Saturday when I tested .

 

[cmaxwell39]

Sorry, didn't get a notification that this thread had been responded to for some reason. My guess would be the extended drop in temperature has caused the corals to slow or stop growing at this point. With the change in multiple parameters (temp dropping/Alk rising) the corals are stressed.

Many are more versed than I am on this though, so maybe someone else can chime in. I am sorry you are having problems. Hope you get it figured out soon.