SPS having issues

[sirfisher]

For some reason my sps polyps don't seem to be coming out like they used to. Our water test are coming out normal and we do water changes frequently.

They are growing but don't seem to polyp. We have acroporas that we are concerned about.

Any tips:?:

 

[krisfal]

I am having the same issue currently so I am going to tag along to see the responses you get.

I am suspecting my problem may be that I am having some difficulties keeping my temperature stable. I have been adding/changing equipment that may be adding heat, but also installed an AC unit in the house which helps keep the tank cooler. But I seem to be struggling with keeping a small range in day to night temperature. I sometimes see 77 at night and up to 84 in the day (If we leave without turning the AC on). I need to replace my heater, that became unreliable and was removed, to keep the temp from dropping so much at night.

 

[apollothesun]

what are your tanks test perameters?

 

[DonW]

Polyp extension is not a good way to determine health. What do they look like at night a few hours after the light go out.

Don

 

[barrierreefcf]

Exact water parameters would be helpful with diagnosis. In my experience the reduction in polyp extension can be related to calc/alk levels, but even more often a fish or invertebrate nipping at the coral. Any dwarf angels, butterflies, or rabbitfish in the tank? Sometimes even tangs go rogue and start nipping. Red Bug infestations will also cause polyp retraction in many cases. Not all though.

 

[acrodesiac]

In my experience the reduction in polyp extension can be related to calc/alk levels,

I have noticed reduced polyp extension when my cal reactor shoots my alk too high(around 14dkh), does that sound like your experience?

 

[sirfisher]

thank you for the advice you all.

 

[kevinpo]

As Don stated polyp extension is not an indication of coral health or happiness. In the wild most Acropora corals do not extend their polyps during the day because they are likely to be nipped at by fish, inverts, etc. The main purpose of the extension is to capture prey food items (such as nano zooplankton) which are much more abundant at night. They can learn to extend during the day in home aquariums especially if there is not enough food and/or light available. In newer tanks (less than 1 year), and tanks without established refugiums there may not be enough natural food which can make the corals extend more and longer trying to meet their daily nutritional requirements. As the tank ages the population of micro organisms hopefully reaches a level to meet those daily needs.

One hour or so after the lights go out check with a flashlight and you should see the longest polyp extension you have ever seen on a SPS coral. It is truly amazing that a coral with such a small amount of tissue could generate polyps up to 1/2" long.
So if your water parameters test the same as usual a nipper or perhaps the scenario talked about above is the reason.

Regards,
Kevin

 

[barrierreefcf]

I have noticed reduced polyp extension when my cal reactor shoots my alk too high(around 14dkh), does that sound like your experience?

I'll be honest...I haven't noticed. I have def seen it reduced during low alk but we so rarely fight high alk that I just don't remember taking note of the polyp extension or lack of.

 

[Frankie]

As Don stated polyp extension is not an indication of coral health or happiness. In the wild most Acropora corals do not extend their polyps during the day because they are likely to be nipped at by fish, inverts, etc. The main purpose of the extension is to capture prey food items (such as nano zooplankton) which are much more abundant at night. They can learn to extend during the day in home aquariums especially if there is not enough food and/or light available. In newer tanks (less than 1 year), and tanks without established refugiums there may not be enough natural food which can make the corals extend more and longer trying to meet their daily nutritional requirements. As the tank ages the population of micro organisms hopefully reaches a level to meet those daily needs.

One hour or so after the lights go out check with a flashlight and you should see the longest polyp extension you have ever seen on a SPS coral. It is truly amazing that a coral with such a small amount of tissue could generate polyps up to 1/2" long.
So if your water parameters test the same as usual a nipper or perhaps the scenario talked about above is the reason.

Regards,
Kevin

Thanks for this info Kevin. I was getting nervous about a few acros not extending. The over all color on them is great and i see growth. Just not the polyp extension I saw in the LFS.