Poor Polyp Extension

[Jaws]

I'm wondering if there is any other possible reasons for getting poor polyp extension other than poor water quality? My water quality is good, the tank has good flow, and there's plenty of light. The corals are still growing and coloring up nicely but still have bad polyp extension. Am I missing anything?

[marie]

Do the polyps open at night? Could you have a fish picking at them? My flame angel used to pick at sps polyps, never did any damage, just annoyed the heck out of the corals

[Aquattro]

Do they extend at all when you feed the tank? I never figured out why my old tank was like that either, but with the new tank, every coral is extended full time. I believe it's water quality parameters we can't/don't measure, maybe disolved organic compounds. Is your skimmer pulling lots of crap? My collection cup gets about 2 inches of gunk every week, and that's with 4 fish, minimal feeding and a bare bottom. You should probably get at least that much in the skimmer.
Other things might be flow, I have tons of flow this time around. Lighting I don't think would contibute, but not sure how to verify that. My temp is stable now, maybe that helps?

[Jaws]

My skimmer has not been performing very well lately. I'm not actually sure if it's because I'm feeding very little lately or because it's just not functioning properly. I believe the skimmer wasn't set up properly for the first three or four months that the tank was set up so when I finally did get it set up properly I would get two inches + every 3 or 4 days. I was battling a lot of hair algae at the time too which I'm sure was as a result of poor skimming. It was pulling out that much for a month or two but has slowed way down now and the hair algae is all gone. I've also cut back on my feeding for the time being. I feed once a day in smaller quantities until I can verify everything is stable for a while. The polyps do fully extend on most of my corals when I feed at night with the exception of a couple less healthy ones. I notice polyps come out a little more when the MH's shut off at night too and just the actinics are on. My temperature is usually pretty stable at around 78 but has got up to around 82 a couple days this summer but not very often. I have most definitely seen my flame and coral beauty angels pick at corals from time to time but usually at the base of the coral and never concentrating on just one. If I watched the tank for 2 hours they might nip at 4 different corals in total and spend the rest of their time picking at the rocks and glass. I just added two Vortechs to the system so I'll see if that helps the flow too. I'm not sure how quickly they should respond but it's been 4 days and I haven't noticed any difference. Thanks for your comments guys. Keep em coming.

[marie]

I would suspect the fish . My sps corals only opened at night when I had my flame angel. They were still healthy and had lots of growth, they just didn't open their polyps up during the day.

[muck]

Im assuming you are talking about polyp extension from acropora. (or other SPS) Check your corals for Red Bugs. I had poor polyp extension from when I had Red Bugs last year. Soon as I nuked em the corals started to extend their polyps a lot more. You will have to check really really close as they are super dupper tiny.

[seashells]

IMHO water flow. Try this link http://www.advancedaquarist.com/2006...m=water%20flow

[Jaws]

Well, I'll tell you what I have for water flow now:

I have 4 1" Seaswirls. One is plumbed to the return and is pushing about 1000 GPH. The other three are plumbed to a closed loop on an Ampmaster 3600 and are pushing about 1000 GPH through each. This is all I've had for about the last 4 months. In the last week I've added two of the Ecotech Vortechs to really try and jack the flow. They're each running at full out which is about 3000 GPH each. I would imagine this should be more than enough for a 180G tank. Since I've only been running it with this much flow for less than a week, could that be the problem or should corals start to respond to the high flow almost right away?

[rickjames]

Let's do a test, you can give me a frag of each of your corals and i will see if they have PE in my tank!

I always found that my acros took a while to respond to better tank conditions, such as better lighting, flow, water quality, etc. I have one acro that never grew or showed any PE for a year. Now all of the sudden it has rapid growth and good PE. Go figure? Strange thing is I haven't changed anything.

Either way i would give them time. My .02.

[Jaws]

Time does seem to be the best medicine in this hobby. I'll see what happens.