Poor polyp extension, good color and growth.

[Phillybean]

Anyone have any recommendations to increase polyp extension? I'm getting pretty poor extension on nearly all my SPS, including a Millepora. It currently looks how a normal Acro would look. On the Acro's you really have to look to see any polyps. Birdsnest has extension but only half what it normally would. Montipora (green cap & superman) are good, as are Zoa's, Torch and Hammer.

Parameters are ok, 1.025, 0 phosphate and nitrate, Calcium 420, DKH a little low at 7 (all API), Mag at 1350 red sea. PH is 8.45. Temperature is 77.5. Tank has been running since September. Lights are T5, 8 bulb 54 watt. Flow is a Jabeo Cross Flow 40 running at 50%. Started losing extension about three weeks ago. Fish are a Yellow Tang and two Lyretail Anthias. It is a 90 gallon tank.

Growth is good and color is ok. Better extension at night but still poor. I feed coral frenzy at night once a week.

 

[lynchmob3000]

Both my yellows nip corals big time. Causes no pe until lights are off. Maybe yours does when your not around. Mine are not shy about cruising thru nipping every sps they come close to.


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[pisanoal]

Anyone have any recommendations to increase polyp extension? I'm getting pretty poor extension on nearly all my SPS, including a Millepora. It currently looks how a normal Acro would look. On the Acro's you really have to look to see any polyps. Birdsnest has extension but only half what it normally would. Montipora (green cap & superman) are good, as are Zoa's, Torch and Hammer.

Parameters are ok, 1.025, 0 phosphate and nitrate, Calcium 420, DKH a little low at 7 (all API), Mag at 1350 red sea. PH is 8.45. Temperature is 77.5. Tank has been running since September. Lights are T5, 8 bulb 54 watt. Flow is a Jabeo Cross Flow 40 running at 50%. Started losing extension about three weeks ago. Fish are a Yellow Tang and two Lyretail Anthias. It is a 90 gallon tank.

Growth is good and color is ok. Better extension at night but still poor. I feed coral frenzy at night once a week.

How new is the tank?

If its a new tank and nutrients are at 0, then there isn't much for the corals to feed on. Especially with such a low bio-load. No food = no reason to have polyps out. If you want better PE, try increasing nutrients and see what. happens. If there truly isn't much for them to feed on, you will have issues in the long run.

 

[reefmutt]

Pe is not something you should necessarily worry about IF growth and colour are still pretty good..
ceryainly, if it was better before and suddenly it isn’t, there may be a pest or water issue but if everything checks out, I wouldn’t sweat it too much. It’s not an absolute indicator of coral health.
3 fish in a 90 gallon tank with 0 for n and p certainly sounds like you could have a low nutrient issue..especially if you say colour is only ok..

 

[DiscusHeckel]

I would increase the organic content of your tank water by not stripping too much nutrients. In addition, if you increase the water flow (random and low velocity) and increase feeding of your fish with protein rich frozen food, such as PE mysis instead of flakes, then polyp expansion should hopefully increase.

 

[eddiereefs]

Did you say the tank was started in September? I had the same problem. Got better p.e as the tank matured. Could be fish as well