What is causing the curled tips of my duncans

[michaelfaulk]

I've had this Duncan for 9 months, color and growth is great, but the older heads have curled tips at the end of the tentacles. I've noticed my cup coral colony is doing the same. Alk 8.3 dkh, 5ppm NO3, no PO4. The biggest change is a drop of both PO4 and NO3 over the last 4 months. Both were very high ~40 ppm NO3

 

[tyler1503]

How's your flow? From the picture it looks like it use a little more

 

[Michael Llabona]

Same thing started happening to me when I dropped my nitrates. I started spot feeding them more often. Helped me at least

 

[Scott.h]

Not enough po4

 

[michaelfaulk]

Flow is med. Flow was turned off for photo. I spot feed twice weekly with mysis or mixes seafood. If too low PO4, why would they not have this issue in the wild?

 

[Scott.h]

Corals need phosphate. Look into the redfield ratio. If your nitrates are 5, which is perfectly fine, remove gfo (I'm assuming you are running gfo to get zero) and let the levels climb to .02. That will help.