How do you get the best PE from your acros?

[Daniel@R2R Verified Admin]

What are the major factors that affect polyp extension in Acropora? What are some things you've done to get better PE?

This photo by @djsmallz of his WD colony got me thinking about this topic. Check out this insane PE on this one!!

 

[MnFish1]

Isn't polyp extension sometimes a function of stress? Most of my acropora only extend their polyps at night. But rarely during the day.

 

[BillyW]

I’m just commenting so I can see what others are saying, but I don’t get or have anything like that in regards to PE!

 

[Wasabiroot]

What are the major factors that affect polyp extension in Acropora? What are some things you've done to get better PE?

This photo by @djsmallz of his WD colony got me thinking about this topic. Check out this insane PE on this one!!

That literally looks like a banana bunch

 

[PeterC99]

PE - Lightning, Flow, and water quality

 

[djsmallz]

Isn't polyp extension sometimes a function of stress? Most of my acropora only extend their polyps at night. But rarely during the day.

I always associated the polyp extension with happiness. The PE of this Walt Disney started when the growth took off and only recedes when bothered. I have a few millies with great daytime PE as well and other across with night time extension.

 

[elorablue]

Colour and PE seem to be the Holy Grails of Acropora keeping. I have good PE on my Red Dragons, Bonsai, Sunset Mille, Orange Passion, Nasuta and a few others but almost no PE on my Shazam, Rainbow Looms, Red Planet, Red Diablo. Granted, these are almost all young pieces that are spending most of their energy encrusting.
I've heard so many different things about PE----more flow, less flow, more light less light , high nutrients low nutrients etcetc ...I'm beginning to think it's just luck LOL.

 

[MnFish1]

I always associated the polyp extension with happiness. The PE of this Walt Disney started when the growth took off and only recedes when bothered. I have a few millies with great daytime PE as well and other across with night time extension.

Yes - I did some reading on this a while ago - if I flip on the lights on some of my acropora at night - it looked identical. I will have to say - that in re-thinking the whole thing - over time - as the coral perhaps was more acclimated to my lights/flow, there was more during the daytime. It may have been that my tank was kept somewhat at a higher PAR level than where I purchased the coral? I guess my point was - lack of polyp extension with good growth and color may not be a 'problem that needs to be fixed'.

Very very pretty coral BTW.

 

[LittleFidel]

I do not own any SPS but the polyp extension on my LPS and even the “happiness” of my soft corals does depend on top-tier water quality. As soon as my favia retracts its feeding tentacles I know it’s time to do a water change.

 

[lemonade]

Isn't polyp extension sometimes a function of stress? Most of my acropora only extend their polyps at night. But rarely during the day.

On the reef polyp nippers like butterflies, angels, etc.. are sleeping at night so it's a natural instinctive behavior for the coral to show more vulnerable polyps at night while fish are asleep. The only case where I've seen PE from a stress related cause is in a very low oxygenated environment.

I have always looked to PE being a top indicator of good health. Having good water params closer to NSW is better. Good light spread, not too much direct light from point source fixtures, and strong indirect flow patterns.

 

[MnFish1]

On the reef polyp nippers like butterflies, angels, etc.. are sleeping at night so it's a natural instinctive behavior for the coral to show more vulnerable polyps at night while fish are asleep. The only case where I've seen PE from a stress related cause is in a very low oxygenated environment.

I have always looked to PE being a top indicator of good health. Having good water params closer to NSW is better. Good light spread, not too much direct light from point source fixtures, and strong indirect flow patterns.

There are plenty of differing opinions - and multiple threads and reasons for polyp extension (and no polyp extension). From my experience, the key is a change in a particular coral. If Coral X always has polyp extension - and suddenly it does not - to me that could signify a problem. Likewise, the converse.

This Poll thread seems to suggest that the majority of members think polyp extension is indicative of a healthy SPS, but there were plenty of dissenters in the comments - and IME, many of those ideas are correct. https://www.reef2reef.com/threads/s...olyps-are-telling-you-something-right.580013/

 

[mattdg]

In my experience, PE comes with stability and time.

The coral will eventually realize that we tend to feed them during the day, doesn't matter actual coral food or fish food. This may eventually teach them to circumvent their biological instinct to feed at night, as they do in their natural environment. I think this is why we observe coral that have been circulating in the hobby longer, express more PE during the day.

As discussed above, not every coral will express PE, which does not necessarily mean it is unhealthy. Also, one system may fulfill feeding needs that another does not, also effecting the degree of PE.

Leave them alone, create as stable an environment as possible, feed your fish and the PE will likely follow.

 

[Cool tangs]

I thought PE was dependent on species more then anything if im being honest, but i could be wrong. High flow can defs reduce PE though from my experience.

Im by no means an expert and havent been keeping acro for very long it took me almost 5 years of having nano before i attempted acropora haha

 

[Cool tangs]

This one gets pulsing flow and has great PE
Sorry for the double post but i just wanted to show off my seccond fav acro

Yellow base with green polyps coming up to purple polyps then a almost ultra yellow gold polyp at the tip. Great PE! Love how many different colours and forms there are

 

[elorablue]

This one gets pulsing flow and has great PE
Sorry for the double post but i just wanted to show off my seccond fav acro

Yellow base with green polyps coming up to purple polyps then a almost ultra yellow gold polyp at the tip. Great PE! Love how many different colours and forms there are

Nice! You're very lucky in Australia being able to buy high quality colonies instead of the 1" fragments

 

[Coronus]

I have been growing acros for 13-14 years and in my opinion good polyp extension is 100% a sign of a healthy happy acro. I agree that Polyp extension comes with stability, good water quality and a healthy system. Thats not to say that all Acros extend their polyps regularly. There are plenty of different species that don’t extend the polyps during the day. Now I have had colonies that were once happy with polyps fully extended daily and then took a turn for the worse and started to die off. At this point the polyps were retracted for months and months until the coral started to become healthy again and then eventually started extending its polyps again. Another note that I think helps with good polyp extension is having a strong number of fish in the system. A good bioload is key!

 

[phillybean]

My Polyp Extension is great, sometimes I worry the color is too good and extension too good that something is about to fall apart. Too many years of Reefing makes me think of the more often bad days than the good. But it's been good for about a year in my 90 gallon and 7 months since my upgrade and still going strong.

Biggest difference to me, is the size of the coral. My frags have decent PE, but on the colonies it's massive. (Frags to me would be 3" - 4" or less, mini colonies 4" - 8" or multiple 3"-4" branches, colonies 8"+).

Flow hasn't effected much, I've had 2 MP40's on the 90, 2 on the 220 and now 4 on the 220, never much difference. Feeding also doesn't make much of a change. When I was feeding the corals every 3 days, to now when I only feed once or twice a month, I don't notice much of an issue.

When I really noticed the difference is when I started dosing AcroPower. Almost overnight my PE exploded. It's pretty much remained now, even when I run out of AcroPower for a week or 2, I don't really see much difference.

Stability is key I think, I currently dose based off the Trident and do 3.5 AWC a night. Nitrates and Phosphate's always very low, too low based on what most people say, but it works for me so I leave it be. When my sand bed starts to get "dirty", I feed Reefroids a couple times a week for a few weeks and it clears up (I take it as Low Nitrate/Phosphate causing a bit of Dino's). I still deal with a bit of Algae here and there, mostly just on the glass and overflows, not much in on the rocks ever.

That said, I think the more resilient the coral, the better the overall health, color, growth and Polyp Extension will be, which may be why the colonies always do better. A couple of my best corals have almost died multiple times due to prior mistakes.

 

[shandoee]

My ORA pearl berry and SC OP had great PE until it just suddenly stopped one day. Then I saw that it started to STN due to heavy metals. Once the STN stopped, it started to have excellent PE again and both are now encrusting rather quickly. For me, PE is indicative of a happy coral. But to answer the question to this thread, I think stability in water chemistry and high flow is the recipe for great PE.

 

[brmc1985]

What are the major factors that affect polyp extension in Acropora? What are some things you've done to get better PE?

This photo by @djsmallz of his WD colony got me thinking about this topic. Check out this insane PE on this one!!

Is this really a WD? Looks more like a Millie to me but maybe it’s just the PE

 

[Hans-Werner]

Isn't polyp extension sometimes a function of stress? Most of my acropora only extend their polyps at night. But rarely during the day.

I think there are two "kinds" of polyp extension: Corals try to catch food at night. Light, specifically blue light, causes polyp contraction. This is at least one reason why corals extend their polyps at night.

The other "kind" of polyp extension is to increase the surface. In my experience pH rather on the lower side and phosphate rather on the high side (+/- 0.1 ppm) increase polyp extension. This makes sense to the coral because only with sufficient inorganic carbon and phosphate it makes sense to increase zooxanthellae exposure to light. This is the main purpose of polyp extension during the day, zooxanthellae exposure to light vs. self-shading.

A reduced zooxanthellae density or zooxanthellae pigmentation, i. e. due to low nitrogen concentration (zeolith methods, maybe organic carbon dosing) may increase the readyness of the coral for polyp extension because the effect is reduced with lower zooxanthellae density or pigmentation. Overall lower photosynthesis produces less pH elevation, less oxygen and less reactive oxygen species (ROS) which in turn may cause stress and coral contraction.