Reduced polyp extensions during the day

[naka]

I'm experiencing reduced polyp extensions on FEW of my acros. Tort, abro, gomezi, echinata are few, but rest of my sps has got great extensions. I thought it could have been my water parameters, but I check my water religiously.

CA - 440 Pho - 0
PH - 8.2 Mg - 1300
Alk - 8.4 Temp - 80

Only thing it might be is my tank is becoming very poor in nutrient lately. Could it be b/c of lack of nutrient in water, so some of my corals are less depended on PE and more relying on light only? Nutrient poor environment could result in corals not relying capturing food in the water column during the day, but rather photosynthesis. That's why we only see PE only on night on some of our sps.

It's just my theory, and I'm glad someone mentioned this b/c same thing is happening to my friends tank here in Houston. Check out the pictures of my tort. I'm getting growth, so I don't think the corals are stressed.

Does this happen when you go into phase 2 or 3 from high nutrient tank?


ORA Tort 11/2004 with nice PE


Same Tort 04/2005 few PE


Thanks,

[Aged Salt]

Hi James,I do like your theory. If p-e has multiple-functions within a coral, then p-e is the end-total result of those multi-factors. p-e is a vastly unknown area, saddled with those who believe a coral with p-e is a "healthy" coral & others who feel that if a coral does not have p-e, it is not necessarily "unhealthy".Evidenced this by your Tort's growth w/o p-e. IME, a persistent change in a coral's p-e is a signal by the coral itself, of a problem, & not a reflection of ZEOvit phases. Bob

[G.Alexander]

James, your corals do not look like having a leak in nutrients. IMO the nutrient poorer the environment is the more polyp expansion the corals are showing. There are many theories out there but this is which I have observed.

With my experience I could tell it is possible to get a better polyp expansion with the following “tools”:

1. Dosing amino acids regular.
2. Using a good carbon which is changed regularly run in a passive water flow.
3. Passing on PO4 absorbers.
4. Providing “optimal” (near NSW) water parameters (KH, Ca, Mg & salinity).
5. Using “elements” spare and also adding them only when they are needed.
6. Making sure there are no critters affecting the coral.
7. Pumping the zeolite regularly.

I would also recommend to watch the “polyp picking” fish careful. They often do this if nobody is in the room or in the front of the tank.

G.Alexander

[Orion76]

p-e is a vastly unknown area, saddled with those who believe a coral with p-e is a "healthy" coral & others who feel that if a coral does not have p-e, it is not necessarily "unhealthy".

I have PE too but my tort is not unhealthy, doc says I just need to learn to contain my excitement

sorry couldn't resist

[naka]

Thanks for the advice Gary. I'll keep my eye on my fish this weekend.