Zoa turning white

[hunt98]

I have some zoas that have a white powdery like residue on them, at first I only noticed it on one, that one has progressively gotten more of it over a couple of weeks, now I am starting to see the hint of it on others, also there is powdery white spots on underneath side got any ideas, best pics i could come up with

 

[worm5406]

A few questions:
age of tank
other inhabitants
dipped zoa prior to introducing
pH
temp
nitrate
nitrite
ammonia
Sg
light type
light intensity
light cycle
feeding method and type
where did you get them (lfs/friend/online)
What was the lighting like from where you got them?

 

[650-IS350]

Paly's incorporate bits of sand or sediment into the mat giving the colony the appearance of a half moon large coral. The polyps of the Protopalythoa sp. are not usually embedded in the base of a mat. They are also larger, and generally have more tentacles around the rim of their oral disc than the Palythoa species as well.
http://animal-world.com/Aquarium-Coral-Reefs/Green-Button-Polyp

meaning its normal

 

[hunt98]

tank parameters

tank parameters

ok here we go

salinity 1.026 according to our new refractometer, we were using a hydrometer, so we thought we had it at 1.025

ph 8.2
Alk 10.6
Mag 13.75

 

[hunt98]

rest of them

rest of them

Nitrate 10
Calcium 440
Phosphate 0
Temp 77.9

We had a 65 gallon and 75 gallon both running over a year, that we combined into this 180 gallon the 180 has been running 2 months. We use RO/DI wate. Our corals came from a fellow reefer and they have been growing like crazy, they dont close up unless they are really disturbed or are eating.

 

[hunt98]

ammonia 0
Nitrite 0

He had them under LED's as well.

sorry about seperate posts, my computer has an issue this afternoon lol

 

[hunt98]

650 thanks for the link, glad i know what these are now.

 

[worm5406]

So with the LED's what type and what colors? What is the light on/actnic/off cycle?

Is this bright compared to where they were?
Feeding?

 

[hunt98]

our led's we have 3, each one is 120w with 2 red, 2 green, 2 purple, 21 16k cool white, 28 royal blue. Whites and blue each have seperate dimmers, blues come on at 12:00 whites at 1:00 then whites off at 10:00 and blues off at 11:00 they are Bridgelux leds blue are at 40% and whites 25%