Too Much Light??

[allyjoe]

I have a 120 gallon reef that is over two years old. Lighting has always been power compacts (240 watts). I recently augmented the PC's with T-5's (4 X 80 watts for a total of 320 watts). I added the T-5's to try to bring out more color of existing coral and possible allow for acquiring some SPS. I kept the PC's running on the same timetable and simply added the T-5 hood next to it. I know that light needs to be introduced slowly, so I only used 2 of the 4 T-5 bulbs (one daylight and one actinic) and only turned them on for a couple of hours per day the first week. Then increased to three the next. After two weeks, I'm having trouble with some of my coral. All water parameters test excellent and have not changed in months. Water temp is consistent at 82-84 (I'm in Florida), which is where it has been since the tank was set up. I have good ventilation and the additional lighting did NOT raise the water temp (I was careful about that). All fish are in perfect health. The only change is the additional light, so this seems obvious, but I thought I would ask. Last night I took the T-5's down and will only use the PC's for the next few days. Most of the corals are doing just fine - only some are now looking bad. My candy cane (which is on the bottom and I've had for almost two years - has always looked great with some polyp division over time) is now showing absolutely no tissue expansion at all, my xenia starting dying the minute I changed my lighting, and now my blastmo merleti. Other corlas like zoos, mushrooms, and favia show no signs of change at all and appear to be just fine. Most of these are near the top and getting much light, but again, were not impacted. Here are my questions:

1) Would just a couple of hours of the additional lighting be capable of doing this?

2) It took almost two weeks to see signs of trouble. Does that make sense?

3) Should I do anything else besides returning to my PC's for now? I really do not want to see the candy cane die. I think I caught it in time for the blasto merleti, but the candy cane looks bad.

4) When and how should I re-introduce the T-5's?

 

[melosu58]

There are a couple ways of lighting acclimation. One is doing what you are doing. A couple hours a day and working your way up and the other is putting screens over the tank and removing one at a time till they are finally off. It`s just hard for me to think that the couple hours a day is doing this to the coral. If you think that the lighting is the problem then create a ledge with your LR and set it under the ledge. Also have you added any new livestock or LR that might have some crabs or predators in it? Is there any corals that are near your candy cane coral. To me the lighting is not the problem.

 

[allyjoe]

I agree - I didnt think that the way I was introducing the lighting would do this. I have not introduced anything new in the last month except the lights - no corals or fish. I'm sure nothing is eating the coral because I've been watching carefully and the tissue is just not expanding. It is strange because most everything is just fine. Only the few items I mentioned. I just checked my timer and I actually did up the light from 2 hours to 5 in a step function manner after the first week. Perhaps that was too much too soon?

 

[Devilishturtles]

T5's can be pretty intense, but I dunno if that much of an increase is enough to do that much damage. I guess it kinda makes sense beacuse it seems only your LPS corals were affected and they are pretty low light corals, whereas zoos and mushrooms can handle a wide variety of intense lighiting usually.

When you say the candy cane looks bad, is it bleaching? brown? shrivled? etc?

Finally, I know you said your temps are consistent, but 84 is slightly high and if it went higher than that, a temp swing can kill corals quickly as well.

Since 2 weeks went by, I'm not thinking the light is your problem either, but perhaps a temp issue. Regardless, sorry to hear.

 

[macman7010]

My guess is you are having a bacterial problem that is effecting your corals. There are so many bacterial infections corals can get I am not going to even try to name them off on here. My best recommendation would be getting a Lugol's Iodine solution. On the package there should be instructions for a prolonged coral dip. Give that a shot and see if you can get the infection under control.

Also there are a variety of coral dips on the market that advertise helping in a situation like yours, perhaps give one of those a try also - it may or may not help. I have used Lugol's dips in the past on diminishing corals with mixed success, but it might work out well; I know several hobbyists who really like using dips. Also, if you dont already I would consider installing a UV Sterilizor on your tank to help cut down on free floating bacteria and perhaps help prevent further infection.