DunkCityReefer
Active Member
Alright sps experts, what are some keys or tips you have to great polyp extension !! 
op2:
op2:
SPS Polyp Extension
- Thread starter DunkCityReefer
- Start date
- Tagged users None
jackson6745
Valuable Member
I believe the opposite is true. The better fed a reef is, while maintaing acceptable nutrient level, the better the polyp extension is. I do not believe that the "food" is the actual reason for the better PE though. The heavy feedings/bioload is a catalyst for an increase in nitrifying bacteria, which feeds the SPS, which creates better PE.
I agree. To me, polyps will extend when water conditions are great and stable, but I have seen greater extension when I don't run any mechanical filtration and allow a lot of particulates in the water. Even more so if you have a large fish population as they are constantly "fertilizing" the coral.
I've always had an issue with too much polyp extension, where sometimes you can't even see the base coral, which is annoying at times. I had to get rid of my spongodes monti because no matter where I put it, high light, low light, high flow, low flow, it kept over polyping and all I would get is a dirty brown colony instead of the contrast of green base and brown polyp.
My screaming green birdsnest looks like a mille with its super long polyps. Expending polyps is a high cost energy process... in my opinion, the SPS would not be extending them if it wasn't being rewarded with some form of return, such as capture of food in the process. I don't consider them hungry, just realizing they can capture even more energy via polyps to go with the energy they get from the zooxanthallae.
I've always had an issue with too much polyp extension, where sometimes you can't even see the base coral, which is annoying at times. I had to get rid of my spongodes monti because no matter where I put it, high light, low light, high flow, low flow, it kept over polyping and all I would get is a dirty brown colony instead of the contrast of green base and brown polyp.
My screaming green birdsnest looks like a mille with its super long polyps. Expending polyps is a high cost energy process... in my opinion, the SPS would not be extending them if it wasn't being rewarded with some form of return, such as capture of food in the process. I don't consider them hungry, just realizing they can capture even more energy via polyps to go with the energy they get from the zooxanthallae.
In my experience it's been flow and feedings. Feedings, a healthy coral is going to be vibrant in color and show good extension. Flow, if for some reason one acropora did not show the same PE as the others I would adjust the flow ( this can drive you insane). Lastly if water chemistry is not right than nothing is really going to make a difference.
I don't run zeo so I can't really speak about what I have not experienced myself. In my own system, I aim for the same ULNS. I'm sure the zeo system is getting the SPS as healthy as possible and with that, they have the energy to expend to their polyps in hopes of catching food items from the water column.
From my understanding zeo starves the corals and this is why its necessary to dose all of these products. The zeo strips the system of all kinds of stuff, so multiple things have to be dosed several times per week. I will agree with Tahoe that if your chemistry isn't right, or unstable that it will be a lost cause. Some of my sps have very good polyp extension, but the ones with notorious long extension don't for some reason. (millepora specifically) They are healthy and my chemistry is fairly stable (within .4 dkh in the last 5 months and 20ppm CA, mag within 150ppm) I really think the issue with mine is a bicolor blenny who has taken a liking at nipping millepora in particular. My sps have a very thick coat of zooax and are probably fed more than 99% of any other in captivity. The reason I say that is because I feed my tank about 10x more than "normal". Excess nutrients aren't a problem either (nitrate 0.5ppm at the moment).
Big E
Valuable Member
From my experience both theories can be correct. Starving corals can have extensive extension to try and capture more light and when little food is available. A coral isn't going to expend the energy to try and capture food unless it's starving or there is food being presented in the water column.
A healthy coral will have good polyp extension, but not excessive. Polyp extension is also species specific.
A stressed coral will have little to no extension or can be closed due to predators.
I don't think it's all that much nutrient related or something that can be connected to readings on a test kit.
Polyp extension can be more related to respiration/oxygen..............ever see how they really reach out when you turn off the power on all your pumps off.
I also don't think you can relate polyp extension in our tanks to how it is in the ocean.
A healthy coral will have good polyp extension, but not excessive. Polyp extension is also species specific.
A stressed coral will have little to no extension or can be closed due to predators.
I don't think it's all that much nutrient related or something that can be connected to readings on a test kit.
Polyp extension can be more related to respiration/oxygen..............ever see how they really reach out when you turn off the power on all your pumps off.
I also don't think you can relate polyp extension in our tanks to how it is in the ocean.
Last edited:
All very good theories. I always enjoy everyone's input into discussions like these. It only helps expand our knowledge base as a whole.
jackson6745
Valuable Member
Because various bacteria are dosed.
Queensreefer
Community Member
I have to mention 2 things that I use and the corals seem to be instantly stimulated as soon as it hits the water. The first one is coral frenzy. I use it 2 times a week and the dam sps look like lps. The second is rotifers. When they are feeding at nite when lights are out I dose a half a cup or so and they go crazy. I always believe the best nutrition comes from the bottom of the food chain. I can't agree with dirty tanks for sps because I run a low nutrient system with great success.
Sorry for crappy pics but all I have for now.
b_rad_G
Active Member
I fail to see how acro would have better extension in a clean tank vs a dirty tank. Just like anything else if no food is present why would the coral use vital energy trying to collect food?
lack of pe can most likely be blamed on something nipping polyps. Even if you never see it if you have a species of fish that is known to nip that will pro ally be your problem. The second most likely is too much flow.
On the flip side extreme pe can be seen under stress conditions. I have often noticed extreme extension of acro after shipping. It is probably due to low oxygen or perhaps high co2 levels. I have also read that in some cases aefw can cause a feeding type response.
lack of pe can most likely be blamed on something nipping polyps. Even if you never see it if you have a species of fish that is known to nip that will pro ally be your problem. The second most likely is too much flow.
On the flip side extreme pe can be seen under stress conditions. I have often noticed extreme extension of acro after shipping. It is probably due to low oxygen or perhaps high co2 levels. I have also read that in some cases aefw can cause a feeding type response.
