Corals Dying - Please help!

[5280Reef]

My Monti and birdsnest have been dying a slow death. I had scary low alk levels about 6 weeks ago 6dkh and have started dosing my tank to pull it up to 9 now. Tank is less than a year old, I have included pictures of the birdsnest and monti both about 6 weeks old and of the entire tank. All perimeters are below;

ALK: 9.5
Calcium: 400
Mag: 440
Salinity 35ppm
nitrate + phosphate are pretty much 0 even though I have turned off my skimmer and am now doing water changes every 3 weeks and started feeding more. With the more feeding still couldn’t get it to register (keep in mind I just use the standard Red Sea test kit which doesn’t seem very accurate for NO3 and PO4). Experiencing what I would consider a bad bubble algae outbreak as a result and still declining health of the monti and birdsnest. What could be going on?

Note, 1 photo has no flash and the other does (hence the change in colors).

 

[Flippers4pups]

Looks to be "bleaching". Lack of nutrients, N03 and P04.

 

[brandon429]

The very first cpr move is to lower light intensity for sure. Cloudy reef conditions sustained a while as you work various options

 

[Flippers4pups]

The very first cpr move is to lower light intensity for sure. Cloudy reef conditions sustained a while as you work various options

Yes, this ^ too.

 

[Seaspirit]

My Monti and birdsnest have been dying a slow death. I had scary low alk levels about 6 weeks ago 6dkh and have started dosing my tank to pull it up to 9 now. Tank is less than a year old, I have included pictures of the birdsnest and monti both about 6 weeks old and of the entire tank. All perimeters are below;

ALK: 9.5
Calcium: 400
Mag: 440
Salinity 35ppm
nitrate + phosphate are pretty much 0 even though I have turned off my skimmer and am now doing water changes every 3 weeks and started feeding more. With the more feeding still couldn’t get it to register (keep in mind I just use the standard Red Sea test kit which doesn’t seem very accurate for NO3 and PO4). Experiencing what I would consider a bad bubble algae outbreak as a result and still declining health of the monti and birdsnest. What could be going on?

Note, 1 photo has no flash and the other does (hence the change in colors).

Is your magnesium really 440? I try to keep mine around 1350 but maybe you’re using a different measurement system. If magnesium is too low you won’t be able to stabilize alkalinity effectively.