Help with coral!!

[Hadders95]

Hello all I am new to the hobby and had the tank from May with fish and coral which went in July into the tank, I am having issue with my Zoa and green star, the last few weeks they have started to look like the image below any help or suggests would be greatly helpful thanks josh

 

[GThompson]

Welcome to R2R. What does your water test show ? Are you running a skimmer? What lighting are you using?

 

[Hadders95]

I do regular water changes (once a week) So the one I did when I noticed the issue 4 weeks ago was:

Salt-1.026
Nitrate-20 ppm
Calcium- 420
KH-143.2
Phosphate-0.50
Mag-1500

The last one was:
Salt 1.027
Nitrate-40ppm
Calcium-380
Kh-125.3
Phosphate-0.50
Mag-around1200

I have an aqua one 120 tank with nothing upgraded, I have a wave maker on the tank and I dose a boaster solution every water change, the tank normally gets around 8 hours of white light and blue light is normally 12 hours. The other coral in the tank is going well which is a mushroom, toadstool and a piece of sps which I can’t remover name of.

 

[Hadders95]

I do regular water changes (once a week) So the one I did when I noticed the issue 4 weeks ago was:

Salt-1.026
Nitrate-20 ppm
Calcium- 420
KH-143.2
Phosphate-0.50
Mag-1500

The last one was:
Salt 1.027
Nitrate-40ppm
Calcium-380
Kh-125.3
Phosphate-0.50
Mag-around1200

I have an aqua one 120 tank with nothing upgraded, I have a wave maker on the tank and I dose a boaster solution every water change, the tank normally gets around 8 hours of white light and blue light is normally 12 hours. The other coral in the tank is going well which is a mushroom, toadstool and a piece of sps which I can’t remover name of.

 

[GThompson]

I don’t see much wrong with your parameters to cause this. It could be something picking at it. Try to get your numbers more inline and keep an eye out for anything bothering them. Mine will close up for a little while if something is off

 

[BeejReef]

I'm not familiar with that measure of alkalinity. Most on here will use dkh or meq/l.

I would be a little suspect of your test kits or procedures. Salinity of 1.027 is a touch high, but the odd thing is your other values. With a higher salinity, you would expect your calcium, magnesium, and alkalinity to be higher than the first test when it was 1.026.

GSP and zoas aren't going to be consuming much in the way of calcium or alkalinity. What's your water source?

Also, what's your lighting. 8 hours of whites is quite a bit, even for stony corals. Could be a total non-issue, depending on your light's power and settings. You could be blasting them with too much light though.

Your phosphates and nitrates are both higher than most would like.

There are a lot of cases where the "why" isn't knowable or even all that important. You can drive yourself crazy.
If it were me, I'd
1) gradually lower my salinity to 1.025
2) Make sure I'm properly and accurately mixing my salt and testing my salinity (refractometer)
3) If salinity and water are good... Look to better tests or using a standard solution https://www.bulkreefsupply.com/fauna-marin-multi-reference-solution.html to make sure I'm reading my tests correctly.
4) Reduce the length of whites on to 5 or 6 hours

Those things can be done over the course of days. Beyond that, if my tests still showed .5P and 40N, there are a ton of ways you could tackle that. The more gradual, the better.