SPS polyp expansion

[Clavius78]

I have an issue (I think) that I've been trying to get my head around for quite some time now. And I was hoping the more experienced people here could point me in the right direction.

My 500 liter reef is mixed with SPS, LPS, softies and multiple clams. There is growth and lots of color. But a large majority of my SPS colonies do not show polyp expansion during the day. All of my acroporas and even milleporas lack any PE. With my acropra tricolor being the only exception. And say, half of my montipora's show any PE. When I look into my tank during the night though, even the most shy acroporas are showing massive PE. The rest is doing fine. LPS is expanding very nicely. Clams are always wide open, showing their colors.

Most striking example is my yellow/whitish acropora with bright blue polyps. It's just a pale twig in my tank, but when I gave a frag to a friend of mine it showed all it's polyps and beauty!

Normally, if PE occurs only during the night, I would suspect a fish would be nipping. But that doesn't make sense, because then also LPS would be agitated. I also don't have any fish that would be usual suspects. There are no angels. Only two Zebrasoma's, 10 chromis, a sixline and two fridmanis.

I have a little amount of stray voltage, that I haven't been able to determine the source of. But I've ruled this one out as a possible cause too, because of the same thinking as with the nipping fish: This wouldn't affect only a small group of corals, but all of them.

My water parameters are as follows:
KH: 7,7 (salifert)
CA: 465 (salifert)
MG: 1250 (salifert)
NO3: 3 (salifert)
PO4: 0,018 (Hanna phosphorus)
Temperature: 25C
Salinity: 1,027.
All are very stable. Except for the CA, which was stable for years at ~425, where I like it, but has gone up to 465. Slowly bringing that down again.
Could it be a more exotic parameter that I'm not measuring?

I use the balling method to maintain KH, CA and CL balance. And I do weekly water changes... Sometimes bi-weekly.

I use the zeovit method to keep NO3 and PO4 in check. If anything, shaking the zeostones and thus releasing the bacterial film should entice PE like nothing else. (According to the experts.) But even that does nothing for my polyps.

My light setup is a mix of LED and T5. But I've been noticing this lack of PE since before I replaced most of my T5 by the LED units. I used to run 6x 80W T5 before.

Any suggestions are more then welcome!

 

[f3honda4me]

Could be wrong light conditions. LED aren't quite as plug and play as T5 and require more tweaking. Try changing the intensity and see how the coral respond.

 

[scooter31707]

IMO, phosphates are a little high for Acros. Also if they are expanding during the night, I would decrease the intensity of the light little by little. May be too much light right now.

 

[Clavius78]

IMO, phosphates are a little high for Acros. Also if they are expanding during the night, I would decrease the intensity of the light little by little. May be too much light right now.

0.018 to high? Really? I thought it was actually beginning to become a little to low?

The light could be a good point. I've ran 6x 80Watt T5 for 8 years. Then I converted to LED units + 2 of the original 80watt T5's. Then, about half a year ago, I thought that I had to little light, so I shoehorned some more powerfull LED strips in the canopy of my tank. Since then, the bright white growth-tips of my purple Stylophora have disappeared.

Then again, I've had problems with SPS PE prior to introducing any LED as well.

 

[sirreal63]

Your po4 is a little low but that in itself won't prevent polyp extension. Have you checked for red bugs? I had them once, my sixline was constantly picking the SPS.

 

[scooter31707]

0.018 to high? Really? I thought it was actually beginning to become a little to low?

The light could be a good point. I've ran 6x 80Watt T5 for 8 years. Then I converted to LED units + 2 of the original 80watt T5's. Then, about half a year ago, I thought that I had to little light, so I shoehorned some more powerfull LED strips in the canopy of my tank. Since then, the bright white growth-tips of my purple Stylophora have disappeared.

Then again, I've had problems with SPS PE prior to introducing any LED as well.

Sorry, miss the 0 in front of the 18.

 

[jda]

SPS don't have to show PE to be really healthy. Some species will show none and some will have a ton even while fish are eating on them. I would worry more about growth and color than PE.

If you thought that the corals were better before the LED, then put the extra tubes back on.

 

[Tripod1404]

If there is too much flow, they wont have polyp extension since it wont be possible for them to catch anything. This is especially true during the day since poly extension shades the rest of the coral and it is more risky.By any chance, do you have different flow patterns for day and night? Like I said before even if flow is the same, coral might just be thinking extending polyps during the day is not wort the loss of photosynthesis and predation risk considering what it cannot catch much anyway.

 

[nashorn]

I too use a Zeovit reactor to feed my sps. It doesn't seem to me the sps response to it
I on the other hand have great PE. It was good before but after doing no water changes for 6 mo . It's the best I ever seem it. ( Not sure if this would work for you) Even my small PM has some PE.
I also tried reef chili and reef riods *sp but notice my sps would put out more of a web like string to capture food.
Do you ramp up and down your light?
Flow ? And pattern?

You mention good PE at night. Try turning on lights when PE is good and see if it all starts to retract.

 

[Clavius78]

Thanks for all the replies. I've got some things to check out. First is my flow. It's a constant flow as it is now. I've set my streamer to pattern and turned it down a little bit. Going to give it some time and see if there's any difference.

 

[zsuman101]

I'm a zeo reefer and use t5s and radions, what is your dosing schedule? Most if not all zeo tanks have incredible polyp extension. Try feeding coral vitalizer , aahc and some oyster feast (The eggs) during daylight hours for awhile. Don't over do it but a couple times per week , they will start opening up soon enough. They need some training. Random flow is also key. And as far as too much flow ... no such thing in an sps reef. My washing machine doesn't move the water better than my ecotechs in my reef. The only way to know if you have too much flow is if the tissue is ripping off the skeleton. Good luck ...zsu

 

[zsuman101]

Btw what is your ph running like? Your phosphate and nitrate look perfect to me. One thing I did was raise my dkh slowly up to 8.2 and it made all the difference in my zeo tank, when I was running in the 7s my reef was a bit unstable... again., good luck... zsu

 

[zsuman101]

Are you using carbon actively or passive? Or might be running too much flow through your zeo reactor, that can surely slam the corals shut

 

[Clavius78]

I'm a zeo reefer and use t5s and radions, what is your dosing schedule? Most if not all zeo tanks have incredible polyp extension. Try feeding coral vitalizer , aahc and some oyster feast (The eggs) during daylight hours for awhile. Don't over do it but a couple times per week , they will start opening up soon enough. They need some training. Random flow is also key. And as far as too much flow ... no such thing in an sps reef. My washing machine doesn't move the water better than my ecotechs in my reef. The only way to know if you have too much flow is if the tissue is ripping off the skeleton. Good luck ...zsu

Thanks for all your suggestions!

I dose Zeobak 5 drops every other day. And 1ml Zeostart each day. Then I use potassiumchloride to keep my potassium at ~400. That's it...

I'm sure going to try the supplements you suggested.

Btw what is your ph running like? Your phosphate and nitrate look perfect to me. One thing I did was raise my dkh slowly up to 8.2 and it made all the difference in my zeo tank, when I was running in the 7s my reef was a bit unstable... again., good luck... zsu

At 7,7 dKH my colors are better, but I can confirm the instability.

Are you using carbon actively or passive? Or might be running too much flow through your zeo reactor, that can surely slam the corals shut

I'm running carbon passively in the sump.

Actually... I increased the flow through the reactor a bit in order to decrease my NO3 even more. Did that yesterday. Thought behind it was to entice the corals feeding response by restricting NO3 some more.

 

[zsuman101]

Thanks for all your suggestions!

I dose Zeobak 5 drops every other day. And 1ml Zeostart each day. Then I use potassiumchloride to keep my potassium at ~400. That's it...

I'm sure going to try the supplements you suggested.




At 7,7 dKH my colors are better, but I can confirm the instability.




I'm running carbon passively in the sump.

Actually... I increased the flow through the reactor a bit in order to decrease my NO3 even more. Did that yesterday. Thought behind it was to entice the corals feeding response by restricting NO3 some more.

increasing flow through the zeo reactor is a no no, that alone can shut the corals down, especially since your nutrients are already quite low