effects of too much lighting on sps?

[110reef]

What is the effect of too much lighting on sps? Will it cause corals to brown out?

I am wondering because I have several corals that are brown when they should be either purple or green. I have 3 400w MH and 4 VHOs lighting an 8' tank. I have been putting my sps high in the tank in an effort to get them to color up. I have also been trying to keep all my parameters low, nitrates and phosphates. However, recently I moved one of my brown corals down to the bottom of my tank, and within a week, it began turning green. So, I am wondering if I have too much lighting. That coupled with some comments that were made on other threads saying that 400w metal halides were too much lighting.

Does anyone have any specific experience with regard to too much lighting, and what the effects are?

Thanks!

 

[TopNotchCorals]

IMO 3x400w MH's on a 8' tank is not too much light at all.It also depends on which corals you are putting high up and if you are acclimating them to the high light value,and also where the coral came from too.If it came from a tank that had it under high lighting then it isnt the lighting that is turning them brown.What are your parameters most interested in your p04

 

[Troylee]

to much light equals bleached out sps..... flow plays just as much importance if not more in the coloration of sps..... the change of flow prolly made it color up..... the main 3 things with sps are flow/lighting/po4 for coloration.... not just lighting....

 

[110reef]

IMO 3x400w MH's on a 8' tank is not too much light at all.It also depends on which corals you are putting high up and if you are acclimating them to the high light value,and also where the coral came from too.If it came from a tank that had it under high lighting then it isnt the lighting that is turning them brown.What are your parameters most interested in your p04

Well, I figured someone would ask that. The only test I have is the el - cheapo API test, which says it is at the lowest value. However, I think the lowest value range is 0 - 0.5 , which doesn't tell you much. I do run GFO.

The coral that turned green is a millie. If anything, it has less flow on the bottom than it did up high. it has been in my tank for about a year, and has always been brown, although occasionally I saw hints of green forming but then it would go brown again, no matter where I moved it. Until I moved it to the bottom of the tank, and it pretty quickly began turning green.

I was thinking that in the presence of too much light that perhaps the coral would add zooanthellae to help protect it, sort of like a sun tan...?

 

[TopNotchCorals]

Well, I figured someone would ask that. The only test I have is the el - cheapo API test, which says it is at the lowest value. However, I think the lowest value range is 0 - 0.5 , which doesn't tell you much. I do run GFO.

The coral that turned green is a millie. If anything, it has less flow on the bottom than it did up high. it has been in my tank for about a year, and has always been brown, although occasionally I saw hints of green forming but then it would go brown again, no matter where I moved it. Until I moved it to the bottom of the tank, and it pretty quickly began turning green.

I was thinking that in the presence of too much light that perhaps the coral would add zooanthellae to help protect it, sort of like a sun tan...?

Mille's dont require high light,I would place it about halfway to 3/4 of the way up the tank under a 400w MH.They need moderate flow but I dont think the flow was the prob in this case.I think your right and you did cook it,just slowly move it up in the tank until you find its sweet spot

 

[inactive]

Interesting.

 

[110reef]

Well, yesterday I moved several of my other corals down to see if they will color up too. My other brown ones are purple monti-caps and a purple digitada. I will let ya'll know if they happen to color up too.

 

[Murfman]

Too much light causes a phemomena called photo inhibition. There is a very large discussion on this on that "other" forum.

 

[Troylee]

Well all the pieces you mentioned are low light sps.... I have never had a piece brown from to much light just bleach our and cook sometimes...

 

[FaviaFreak]

Yup, one side affect of too much light is photoinhibition, where too much light for too long can cause the coral to not be able to photosynthesize (sp?) In essence the coral will brown out or have drab colors. This is one possible reason to why your corals look blah..there are way too many variables to make this case a slam dunk solution to your particular problem, although I have dealt with similar issues and the solution was cutting back from a 10hr photoperiod to a lesser one

 

[condor]

Yup, one side affect of too much light is photoinhibition, where too much light for too long can cause the coral to not be able to photosynthesize (sp?) In essence the coral will brown out or have drab colors. This is one possible reason to why your corals look blah..there are way too many variables to make this case a slam dunk solution to your particular problem, although I have dealt with similar issues and the solution was cutting back from a 10hr photoperiod to a lesser one

beat me to the photo period suggestion, 8 hr for halides is best IMO

 

[Murfman]

Article from Dana Riddle on PI;

Reefs.org: Where Reefkeeping Begins on the Internet - Photosynthesis/Irradiance (P/I) Curves and Why They Are Important to ReefKeepers

 

[110reef]

This is interesting stuff. My photoperiod for my halides is 5 hours except on weekends when it was 16 hours. I have now changed it to 5 hours every day. My VHO's are on for 16 hours. Maybe I will cut them back some too. I am still thinking that the light intensity has been too much as well, so we'll see how my experiment of moving the corals down pans out. All this time I was blaming it on high phos and nitrates, it would be nice to find out it was lighting after all.

 

[Murfman]

I know my lower light LPS change colors due to too much light. I have a Van Gogh's Starry Night Favia that is brown with baby blue stars and it turned almost all blue, from too much light. I moved it back down and it slowly started to regain its original coloration. I have a Skittles Acan and too much light and the orange turns red and does not change back.

 

[lars]

ken, i have sps sticking out of the water in spots in my 120 and i run 2 400w ushio 20k + 2 110w vho( 454 & actinic) and have great color. i don't think it's the light. i really think it's nutrients. have you tried to use microbak or something similer. i really beleive it would help. hope this helps

 

[110reef]

ken, i have sps sticking out of the water in spots in my 120 and i run 2 400w ushio 20k + 2 110w vho( 454 & actinic) and have great color. i don't think it's the light. i really think it's nutrients. have you tried to use microbak or something similer. i really beleive it would help. hope this helps

Hey, lars!

I did start the MB7, and was several weeks into dosing. I mainly was doing it for byropsis eradication, which I did accomplish. I stopped after a while, though. I have also changed my GFO several times, but not in the past 3-4 weeks. In testing my water, the phos tests low with the kit that I have it is hard to say what the level really is, but it is low. The nitrates test at 10, which isn't too bad. So, maybe it is nutrients, but I was surprised at the millie turning green within days of moving it to the bottom of the tank. No other changes have occurred in the tank. Also, the polyps have begun sticking out too - as you know a millie should be quite hairy - this one has not had the polyps sticking out. So, given that nothing else has really changed in the tank, I chalk it up to being moved lower down. Time will tell. Also, I have 14K reef optic bulbs, which may have more par than a 20K bulb. I don't know. I'll see how the corals do on the bottom...

 

[Troylee]

invest in a hannah checker... best 40$ i have ever spent...

 

[110reef]

I didn't realize they were that cheap. I may have to look into that...

 

[smokenax]

how far are your light fixtures from the water surface and how old are your bulbs ? all my millis are up high and have good coloration,also flow is turbulent.

 

[110reef]

Lights are about 6" above water level. Bulbs are now about a year old and need to be replaced, but the same bulbs have been there and the corals have been brown all along.