Why does this happen to my polyps

[Moonlightreef]

Hey everyone
I notice some of my Polyps do this to their tenticals . Does anyone know why ? The tank is loaded mostly with SPS and polyps . My Alk is very stable so is CA.


I have 55 G display with 20g sump
AlK 8.4
CA 420
Mag 1380
NO3 3pp
NO4 undetectable

5-6 g WC once a week
bubble Magus NAC7 skimmer
2 OR T247 LED lighting Channel one 60% Channel two 26%

 

[Triggreef]

Increase light lately? Mine do that if I increase light too fast. then they ball up if I really increase it way too fast. (Like if I move from my frag tank to main tank)

 

[Moonlightreef]

I only increase 5% white in the past month but i decrease it down 5% yesterday thinking that could be it

 

[joshporksandwich]

Light or a chemichal swing.

 

[Aqua fire/medic]

I've had this happen before.....IME it does spread to other zoas. Not sure if it's bacterial or fungal but it seems to start with one or two polyps, then spread through out the colony. I've had good results with lugol's dips and chemiclean dips. Not on the same day though.

 

[Moonlightreef]

i think it was my lights , i had to raise it down a bit , hope this will fix the problem . I will keep update if think look better

 

[tigerdragon]

How high above tank are your lights? Best is around 10"

 

[Moonlightreef]

i think they are 9