Issues with Several Zoanyhid Colonies

[BenitaSolo]

Having a hard time identifying the issue and also a hard time searching for the right descriptors. pictures attached. Notice that the zoas are curling upwards. More colonies are being affected as time moves forward.

quick stats
-tank is 18months old
-1.026 ppm
-.1 nitrates (detectable in Salifert)
-18ppb PO4 (.03ish ppm)
-8.5 alk
I do not have an iodine test kit.

Recent changes: I have been halfway battling amphidinium dinoflagellates. They are sand dwelling and less toxic. I have been slowly raising nutrient from non detectable to what you see above.
2 weeks ago I decided to buy a bottle of VIBRANT algae killer because I read it might be good against dinoflagellates. This curling upwards issue started about 6 days after the first dose and slightly subsided until the second dose which was 5 days ago. I performed one 15% water change between the doses and refreshed the Rod .8 carbon I run in bags. (6 days ago)
I am considering that maybe the Vibrant is outcompeting, thus killing, the dinos and the dinos are releasing a toxin. (All other corals unaffected)

I have also been renovating a room on the same level of the house. This includes- paint, primer, drywall mud, mud sanding, varnish sanding. Just a thought....

Does anyone have anything to add that can help?!?

 

[Dsnakes]

What type of lighting do you use and how deep is your tank? They seem the be stretching for light.

 

[BenitaSolo]

What type of lighting do you use and how deep is your tank? They seem the be stretching for light.

The lights are 15" above the surface of the water and the tank is 16" deep. Zoas on the sand bed. 6' tank running 3 gen 3 radion XR30 on the LPS/Softies schedule.
I feel reasonably confident The zoas are not reaching for light. This problem occurred more or less over night. It's happening in mass and seems to be effecting the entire colonies while other are unaffected. Most of these are from 5ish polyp frags that have been in the tank for over a year.
Thoughts?

 

[danschoenherr]

Any other corals Affected? What intesity are you running your Radions?
Maybe by adding the fresh carbon, the water cleared up and increased your Par, more than those zoas are used to.
They do look like they are stretching a bit. I am still trying to get the right program/intensity for my Radion on my zoa/paly tank

 

[BenitaSolo]

Any other corals Affected? What intesity are you running your Radions?
Maybe by adding the fresh carbon, the water cleared up and increased your Par, more than those zoas are used to.
They do look like they are stretching a bit. I am still trying to get the right program/intensity for my Radion on my zoa/paly tank

The radions have been running at the same intensity for the year + the zoas have been in the tank and I run carbon fairly regularly so the water stays pretty clear. I believe I run at about 60% overall intensity. This translates to around 40% in the LPS/Soft Ecotech preset.
All of the other corals are doing great. Mostly LPS and montipora. I think the only other softies in the tank currently are various mushrooms...
I do know that dinos are toxic. I don't know if they release the toxin when the die or are just toxic in general...
Could an increase in flow make the zoas look like this? I did just turn the dial on my gyre 2-3 notches up but honelty it didn't really look like it made any difference at all to the other corals, the sand bed, the anemones, etc... and it hasn't affected all of the zoas. I will turn the water flow off for a few hours tonight to see what happens.
If you look at my history you will see that about 2 months ago I ran a fish bendozole dose to get rid of branching hydroids. I lost two big toadstools but removed them from the tank before they 'rotted away'. It also killed some GSP (intentionally). The snails survived, the stars survived... and the hydroids survived! jerks.
I followed the water change/carbon protocol after the dose and there are no reported issues with bedazole and zoanthids. This was all about 8 weeks ago I think.

 

[BenitaSolo]

Bump- problem is still going on and I’m still not sure why.
Nitrates are testing at .5ppm today. Is that too low? Lps and sps seem fine...
Phosphate is at .04. Too low? I can’t get it above this level reliably. I feed often but don’t want to dose a product like flourish
Alk is 9.5
Calc is 400
Mag is 1580- high but It’s been high since the start... using Fritz Pro Salt and not using any kind of adds with mag in it.

Help me figure this out! Any specific tests I should perform?
Thanks reefers

 

[RUCNNEfish]

My LFS has said that drywall dust will harm some corals and fish. They had to do 100% water changes on the total system. Also said carbon doesn’t work good enough.

 

[BenitaSolo]

My LFS has said that drywall dust will harm some corals and fish. They had to do 100% water changes on the total system. Also said carbon doesn’t work good enough.

While I appreciate the input some googling and reading seems to suggest that drywall dust is pretty harmless.
Maybe t was the varnish I sanded. The tank is 2 rooms away and around the corner and for most of the work I had plastic hung up. There isn’t any dust on the light fixtures or wasn’t any sheen in the water surface so I want to assume not much dust got in the tank. It could have always been something on my hands...? I’m typically pretty careful and was conscience of the work so I kept fresh carbon supplied.