Rasta zoas


Reefing newb
I bought some pricey Rastas (luckily there were only 3). After about 1 week I noticed they shrank then dissappeared.I noticed that one of My other zoas are starting to do the same. Any suggestions?
The only thing that was high was my nitrates (40ppm) which I started correcting yesterday. My lighting is a Marineland reef capable LED.
I add Special Blend Microbe-Lift over 24 hours ago because I had to work and couldn't do a water change. This AM I noticed the ppm was still at 40. I started the Vodka method this AM before heading to work and I may have to try a water change tonight...
Are you using RODI water when doing your water changes? Whats your stock list look like? In my opinion you shouldn't ever have to dose anything in order to keep nitrates down.
Yes, I use a 5 stage RODI and I did a 20% water change 12 days ago but nitrates shouldn't be that high. I have a 44 gallon with 2 turbos, over 10 tonga snails, and a couple of porcelain crabs. As for fish, I have 4 clowns, 1 yellow tail damsel, and 1 firefish. I feed my fish frozen food once per day just enough for them to eat up in under 2 minutes. I ordered some peppermint shrimp, more tongas, and a red sea star to help with clean up which should be arriving today. I think part of the issue is such a limited CUC. I have a 5 staeg HOB filter that I replaced the filter on 2 days ago. I haven't ran a skimmer in a couple years but that hasn't been a huge problem with regular water changes.