SPS/cyphastria seems unhappy

[Oldss72]

Hello - I am looking for help - I have a 120 gallon tank - and in the past week my 1 sps and both of my cyphastria have started to look rough. I believe it might be due to low nutriants - but I am looking for suggestions.

I did a 35 gallon water change a few days ago - but no change. Also - the acapora has been getting what I thing is cyano growing on it daily. I blow it off with a turkey baster - but it comes back. Areas not covered have polyp extenaion - but it looks like the color is fading somewhat.

Last test was nitrates : 2ppm, phosphate .02. Mg 1180, alk 9dkh. Calcium 420, ph 8.2. Temp 79.9. Red sea test kit - except for phosphate hanna checker. Everything else looks great. Looking for help. No Other cyano in the tank.

I did turn off my gfo reactor and slowed my vinegar dosing - though it hasnt changed in months. My nitrates used to be a solid 5 - now they are lower but not 0.

 

[blaxsun]

The cyphastrea is an LPS but often sold as an SPS, but I'm thinking it's just not getting enough light in that corner. I'd try repositioning it about midway up your rocks and see how it fares. I have mine in around 125-ish PAR.

 

[TopShelfAquatics Verified Sponsor]

As stated above, those pieces may not be receiving enough light, but if you are seeing cyano pop up that is usually due to a lack of flow in the tank. From the looks of it your tank is pretty tall and the powerheads are higher up on the tank. You most likely have some dead zones especially near the bottom of the tank. I would suggest looking in to adding another powerhead or so. Or maybe bring one down and turn up the power. Corals need good random flow. That will also help with getting rid of that cyano.