Coral problems

I had a slight hair algae problem and I also needed to paint the back of my fish tank black so I decided to take off all equipment including the light except the filter for 3 days. I turned back on the light and left it on for like 10 hours accidentally. I usually only have it on 6 hours a day. The next day I noticed one of my corals has a white spot on it also it seems like the outer edges seemed to have lighten up as well. Did I sun bleach it or is it some other disease or pest or some sort? Also my pulsating Xenia’s and green star polyps have been shrinking in size they are about the 1/4 of the size that they were a few months ago. Any ideas why this may be happening? All my levels are normal but my nitrates were like 20-30 but my phosphate is .03 ppm. I recently purchased a protein skimmer and rodi unit to help combat nitrates.

 

I see both green algae as well as plants growing which would use the phosphate and provide an incorrect reading.

I doubt the extra 4 hours is the cause of the white dot, the monti seems to be receding at the edge, normally we would see white, new growth all around the edges.

20-30ppm for nitrate maybe OK for softies at most but the SPS won’t like that much. The target here is 2-5ppm, all corals ok with this level.

I know you say all parameters are OK, but we need all 8, especially Alk and MG and how long these have remained at that level in order to provide some value added advice.

When softies start to recede, always suspect a water stability and quality problem firstly.

If I was to guess, a fluctuating Alk is what I would check first, with a monti, consistent 8.5-9.5 is good

 

Here are my current levels salinity is at 1.025

 

Maybe it is the plant growing in your tank it looks like some type of caulerpa

 

In the last photo it looks like the algae is growing on the coral you may want to remove the algae

 

How do I remove the algae from the coral?

 

This one?

 

Numbers great!
How long have they been that way?

 

Remove the algae and possibly the coral.

 

Note you have very lush plant life in your tank and this is counterproductive to coral in the DT.

It would mean your phosphate is not 0.09 but substantially higher.

These two things will not go well together, remove all plant life, scrub off with a toothbrush, and run GFO to mop up the phosphate organic.

You may consider carbon dosing with Nopox which will bring your nitrate down to day 5ppm

 

Its all about tank maintenance I had caularpa species that looks good in the beginning but becomes very dominant I removed it by hand and watched for more growth when I saw more growing back I removed it I was able to remove it without removing my rock but I did loose some of my sand.

 

Then why do people have refugium with plant life and algae scrubbers to grow other plant life to remove phosphates and stuff if it is bad for the dt? Different type of plants?

 

Because they separate the algae from the life in the tank

 

And in a separate refuge, the plant life can be harvested and removed from time to time and the phosphate absorbed goes as well.