Polyp Extension

[ShawnM]

Wanted to get a couple people's idea on what make polyp extension greater or smaller. Methods to help, what cause it, and ideas to get greater polyp extension.

I have noticed in my tank I seem to not get great polyp extension (decent but not great) but corals still look very happy and are growing and colors look good.

[FarmerTy]

I'm assuming you are talking about SPS polyp extension?

-strong, random flow

-no parasites

-stable parameters for a length of time

-decent amount of available foods in the water column (bacteria, detritus, plankton)

-fish that don't pick on the corals

-CUC that don't disturb the corals

-low phosphates

[Dan H]

It also totally depends on the SPS. Certain ones seem to never put their polyps out, and others just love flapping in the wind. I've noticed some must also sense food in the water. When we feed, or something spawns, sometimes they'll open up a lot more than normal.

[Dan H]

Oh, and check after lights out. Some of mine will only come out at night...

[ShawnM]

I'm assuming you are talking about SPS polyp extension?

Yes I meant sps thought about after I went to bed but figured you guys would figure it out

[Nathan]

Sponge power from the zeovit line of additives. Worked wonders for my 15 acros, and 4 monti. 1/4 of growth a week, and very noticable polyp extension within first few days of use.

[Gig 'em @ NDstructible]

I noticed an increase in PE when I started dosing AcroPower. I agree with what Ty said too, all of those things are essential to get the coral polyps happy enough to extend out.

[Timfish]

"Feeding" and species preference. Feeding for corals is a VERY complex subject and corals have a heavy need for nitrogen and phosphate and will pull both directly from the water if not able to get it from grab ing partcles or plankton from the water. Quoting Charles Delbeek "Our crystal-clear aquaria do not come close to the nutrient loads that swirl around natural reefs. And so when we create low-nutrient water conditions, we still have to deal with the rest of a much more complex puzzle." Coral, Nov/Dec 2010 pg 127. We also need to remember we are dealing with thousands of species, variants and almost certainly domesticated strains, lumping everything into a few broad categories like "SPS", "LPS", "Softies", etc. that have no scientific basis and certainly no relevance for husbandry only adds confusion to the issue. Looking through Veron's "Corals of the World" just with the Acropora genus we have related species that live in mutually exclusive habitats.

Here's a few examples from one of my systems. The Acropora millipora in the first picture always has it's tenticles out while the A. valida rarely does.

In this picture the A. tortusa var. also always has it's tenticles out and the Ora Hawkens A. echinata never does.

Water parameters for last three months (tested weekly around noon):

Alkalinity 6-10 dKH

pH 7.8 - 8.1

Temp 76 - 80

Salinity 1.022 - 1.025

Last tested 08-15

PO4 ~ 1.5 mg/l (Elos)

Nitrate 0.0

Calcium 380

Magnesium (Red Sea)

Flow is very low around the milli and valida. Here's a video of the flow around the tort and echinata (taken last year when experimenting with in tank STN treatment with iodine):