Negative Intense Lighting Effects on Ps -n- Zs

[Wy Renegade]

Thanks Wy! No I didn't use the screen method not really sure what that entails. Yes I was referring to PC's. I was hoping that it was light related. If it's something else I sure can't find it

Jamie the screen method is well described in this feature article.
Photo Acclimation of Corals

[MUCHO REEF]

Good discussion Wy Renegade.

Your questions were,

"Besides the obvious bleaching of a coral, what are some of the signs that indicate that a polyp is receiving too much light?"


If we are speaking solely of zoas and palys here, the quickest and most obvious and
tell-tale sign/indicator, is near instant or slightly delayed polyp retraction. Zoas and palys are highly adaptive to most any kind of lighting, I agree. Yes, they will even survive under PC lighting alone, with shallow dwellers always being placed higher on ones reef. I kept a tank full of zoas and palys under PC's alone. So how can the reaction be delayed instead of instataneously? Zoas and palys are photosynthetic or ( zooxanthellate) creatures, which derive their energy from sun light or tank light for nutritional uptake. Some corals are azooxanthellate, ( those which thrive in darkness). Delayed retraction as a result of intense lighting in some zoas and palys can happen as they are well aware that they must remain fully expanding to feed whether it's via photosynthesis or to exhibit a prey capture response to food through their intestinal cavity, while others will feed on zooplankton. I have read and heard some say that the expulsion of wasteful zooxanthellae is a sure sign of pre bleaching or light shock. On the contrary, not always true, they will expel under perfectly normal conditions for absolutely no reason at all. Some will even do it if you place your hand in the water, move them around or briefly block their light source. We've all, or should have seen this if you are or have kept an abundance of zoa and palys. So I would say retracion, whether instant or slightly delayed, is what I'd look for.



"What is the overall time frame during which this can and does occur? Minutes, hours, days, weeks, or even months? "

It can vary, most often instantly, but for sure within 24 hours to 48, you will see signs of not only retraction, but the polyps will often begin to shrink with rippled stems. A friend of mind had dual 400 watt HQI's or was it MH's, I can't remember. He didn't acclimate them and placed them low, mid tank and high on the reef. I mean he had the most stunning color I have ever seen. I mean the expansion on most were craazy. But just 48 hours later, he experienced more retracted polyps then those expanding. This is where acclimation with screening would have helped dramatically.

I firmly believe in light acclimation for any new arrivals with the first day being total and complete darkness. If you can cover the entire face and sides of your tank, that is even better. On the second day, I have always, I mean always recommended and practiced running my actinics only and only for half of the photoperiod. On the 3rd day, beginning with a 3 hour dawn, followed by 4 hours of daylight without actinics, then the final 3 or 4 hours of dusk with actinics only, and I have never, I mean never had any issues. On the 4th day, just follow your normal photoperiod and you'll be surprised. One caveat here, one should always, always inquire of the previous lighting conitions, type, wattage, k value, height of placement and lenght under that lighting scheme and in the tank itself. It is vital to know, even with proper acclimation, and if these polyps were aquacultured with a few T5 bulbs, and you placed them high in your system under Dual HQI 250 watt 10 k's, you are going to have some issues. This is a prime case in which at lease 6 layers of screening must be utilized. Or at best, raising your canopy or lighting source with slow and gradual lowering back to normal. When I use to sell and ship all over the country, and whenever the buyers followed this process, they too never had an issue. More often than not, if packed, shipped and cultured properly, most polyps will expand within minutes to a few hours in complete darkness.

I hope this helps.

Mucho Reef

[Wy Renegade]

Good discussion Wy Renegade.

Your questions were,

"Besides the obvious bleaching of a coral, what are some of the signs that indicate that a polyp is receiving too much light?"


If we are speaking solely of zoas and palys here, the quickest and most obvious and
tell-tale sign/indicator, is near instant or slightly delayed polyp retraction. Zoas and palys are highly adaptive to most any kind of lighting, I agree. Yes, they will even survive under PC lighting alone, with shallow dwellers always being placed higher on ones reef. I kept a tank full of zoas and palys under PC's alone. So how can the reaction be delayed instead of instataneously? Zoas and palys are photosynthetic or ( zooxanthellate) creatures, which derive their energy from sun light or tank light for nutritional uptake. Some corals are azooxanthellate, ( those which thrive in darkness). Delayed retraction as a result of intense lighting in some zoas and palys can happen as they are well aware that they must remain fully expanding to feed whether it's via photosynthesis or to exhibit a prey capture response to food through their intestinal cavity, while others will feed on zooplankton. I have read and heard some say that the expulsion of wasteful zooxanthellae is a sure sign of pre bleaching or light shock. On the contrary, not always true, they will expel under perfectly normal conditions for absolutely no reason at all. Some will even do it if you place your hand in the water, move them around or briefly block their light source. We've all, or should have seen this if you are or have kept an abundance of zoa and palys. So I would say retracion, whether instant or slightly delayed, is what I'd look for.

"What is the overall time frame during which this can and does occur? Minutes, hours, days, weeks, or even months? "

It can vary, most often instantly, but for sure within 24 hours to 48, you will see signs of not only retraction, but the polyps will often begin to shrink with rippled stems. A friend of mind had dual 400 watt HQI's or was it MH's, I can't remember. He didn't acclimate them and placed them low, mid tank and high on the reef. I mean he had the most stunning color I have ever seen. I mean the expansion on most were craazy. But just 48 hours later, he experienced more retracted polyps then those expanding. This is where acclimation with screening would have helped dramatically.

I firmly believe in light acclimation for any new arrivals with the first day being total and complete darkness. If you can cover the entire face and sides of your tank, that is even better. On the second day, I have always, I mean always recommended and practiced running my actinics only and only for half of the photoperiod. On the 3rd day, beginning with a 3 hour dawn, followed by 4 hours of daylight without actinics, then the final 3 or 4 hours of dusk with actinics only, and I have never, I mean never had any issues. On the 4th day, just follow your normal photoperiod and you'll be surprised. One caveat here, one should always, always inquire of the previous lighting conitions, type, wattage, k value, height of placement and lenght under that lighting scheme and in the tank itself. It is vital to know, even with proper acclimation, and if these polyps were aquacultured with a few T5 bulbs, and you placed them high in your system under Dual HQI 250 watt 10 k's, you are going to have some issues. This is a prime case in which at lease 6 layers of screening must be utilized. Or at best, raising your canopy or lighting source with slow and gradual lowering back to normal. When I use to sell and ship all over the country, and whenever the buyers followed this process, they too never had an issue. More often than not, if packed, shipped and cultured properly, most polyps will expand within minutes to a few hours in complete darkness.

I hope this helps.

Mucho Reef

Thank you Mucho for the incredibly detailed and informative response. I'm sure that many will find it to be of use. I would simply add that my observations are the same as those of yourself and Chris. I would also expect that the initial response to too intense light will be closure/retraction of the polyps within a relatively short period of time.

Anyone else have any similar thoughts or observations to add to the previously mentioned observations?

In the event that one has failed to properly light acclimate, and polyps have closed up/retracted. What should one do? Does one simply leave the polyp sitting in the same spot in the hopes that it will eventually adjust and reopen, or does one attempt to move the polyp into a more shaded area in hopes that it will reopen?

From my own observations, I would suggest that a possible solution would be to move the polyp into a more suitable location, perhaps one where the polyps are sitting slightly under the edge of an overhang or rock so that they receive some additional shading. Further, I would recommend that the chosen shaded position would be one where the flow rate was slightly higher, but not too much higher than where the polyp was originally placed. As a final step, I would recommend that one envelope the tank in darkness for a full 24 hour period, and when relighting after the 24 hour rest period, use an adjusted lighting schedule as proposed by Mooch, or multiple layers of screen.

Any further observations or thoughts from others?

[Wy Renegade]

Thinking about this a little more last night, brought some additional questions to mind.

If one is running t5 rather than PCs or MH with daylights and actinics. Is running some of the blues with the daylights bulbs ok for the daylight portion of the acclimation process? I ask, because I run two blues as morning evening and a combo of blues and 20,000K daylights as my full sun. Generally if acclimating I shut off or reduce the daytime portion of the light, but blues are part of that, should I be seeking to eliminate the blue all together during the daylight portion of the acclimation process?

Second, if speckling (such as that found in some PE morphs like speckled green), is a result of being right on the verge of too much light, in order to maintain the speckled look does one have to continue to exposte them that extreme of lighting, and is that healthy for the polyp?

[schminksbro]

This is a tank that I had a few years ago grown under Power Compacts.

I personally would love to see those who are *successfully* keeping any zoas under 10k cf. I for one have not been able to.
Sir has been following along with me on this issue I've had for some time. My tank is mature and stable. Therefor I must assume it has something if not everything to do with poor lighting conditions.
They've most likely come from a stronger light source-not to many peps growing zoas under cf for selling.
Just my observation of my tank.

Radio Active Dragon Eyes=8g tank-18w 10k-18w 420/430nm on sand bed


However they no longer look like this. I raised them higher, they began to fade. Brought them back down for several weeks, still faded. Now they're back up and I hope they'll adjust

[Wy Renegade]

This is a tank that I had a few years ago grown under Power Compacts.

Very nice Andy! That is a gorgeous tank that clearly shows Zs-n-Ps can be successfully kept under PC lighting. Thank you so much for taking the time to share.

[Kev Apsley]

Kev, mine have done the same, I'm actually wondering if its from too little light. Several I know keep them high under pretty intense lighting.

I just moved mine under higher light to see if that helps I will keep ypu posted

[MUCHO REEF]

Thinking about this a little more last night, brought some additional questions to mind.

If one is running t5 rather than PCs or MH with daylights and actinics. Is running some of the blues with the daylights bulbs ok for the daylight portion of the acclimation process? I ask, because I run two blues as morning evening and a combo of blues and 20,000K daylights as my full sun. Generally if acclimating I shut off or reduce the daytime portion of the light, but blues are part of that, should I be seeking to eliminate the blue all together during the daylight portion of the acclimation process?

Second, if speckling (such as that found in some PE morphs like speckled green), is a result of being right on the verge of too much light, in order to maintain the speckled look does one have to continue to exposte them that extreme of lighting, and is that healthy for the polyp?

ANYONE ?

[Wy Renegade]

Really? Nobody else has any answers, comments or questions?

[Sir Patrick]

in order to maintain the speckled look does one have to continue to exposte them that extreme of lighting, and is that healthy for the polyp?

In my experience, yes, you need to maintain the intence lighting- or the polyp will morph back to normal.

Is it healthy for the polyp? Good question...one that I am not possitive on. I would guess it is ok though. I have gotten good growth and had healthy polyps that have exhibited this morphing from intense light. The more light the better, right? At least till it gets to be too much....