SPS Polyp Extension

[Felixc395]

I was wondering what good polyp extention is for SPS corals. I've had some problems with my sps growing recently because their polyps won't expand. I have no idea really.

Could someone post some up close pictures for me so that I can see what good polyp extension looks like?

Thanks so much!

 

[acrodave]

polyp extension is not always a sign of health. in the wild they dont come out till night

 

[rholguin]

+1 on the above. I don't have any polyp extension during the day, but at night my sps have great extension. Do you have any nippers in your tank? How is your water flow? What are your parameters? There are different factors as to why you are having problems with growth. More specs on your tank would help.

 

[flyin2jz]

x3. I personally believe there is a bigger chance somethings wrong if u have a ton of pe during the day. They only come out at night in the wild.

 

[Felixc395]

Alright some specs for my tank is that i have a 4 bulb T5 HO AquaticLife system on a 17'' high tank. I have 3 ATI bulbs and one UVL bulb. I have about 1000 gph of flow for my tank with three powerheads.

My water parameters are:
Nitrate: 0ppm
Phosphate: 0ppm but suspicious of my API test kit
Calcium: 450ppm
dKH: 11
pH: usually lower than 8.0 and changes

I have about 4 sps corals and three of them are fading in color or bleaching. My sps never extend there polyps so that was a concern.

 

[njfish77]

What could it mean if you have really good pe during the day but not much at night?

 

[acrodave]

I think we see pe during the day is because there are no predators messing with them

 

[Whisperer]

Once corals get used to a threat-free environment, their polyps will extend in the daytime, exposing more surface area for zooxanthellar photosynthesis. Feeding tentacles at the tips are more prominent at night to feed on nocturnal preys.

I have yet to see a great polyp extension on a dying coral, even at night. I would say, with few exceptions, that something is wrong if your corals do not open in the daytime.

 

[jhawkor]

My SPS show minimal PE during the day because I have angels. They feed at night and continue to grow so I'm not worried.