Lighting Issues with Corals
 

I have been having on going problems with my lighting. I have a 90 gallon with 2x 250 watt MH lights. For months I have been using screens to cut the light back and every time I think that I am finally getting somewhere the corals look terrible the day after when the halides come on again. I was down to one screen on each side yesterday and now my frogspawn and hammer corals are closed up as soon as the lights come on and I have put more screens on again. My parameters are all good so why is this continuing to happen? I also had 2 colt corals that disintegrated at different times over the past month or so. I keep thinking there is something wrong with my tank but I am at a loss as to what. Any ideas?

Leanne

Typically, if I were to use screens on new corals, I'd do it for up to a week. After that, they should be fine. Maybe not a lighting issue?

Just a thought...are these double ended, and if so, do they have UV covers?

How long are you running the lights for each day and how high are they off the tank? I recently upgraded to 2x 250 mh from 2x 175 mh, and had to cut back my light schedule. Try running them for shorter periods and slowly increase the time over a period of weeks. Also you may have your corals too high up in the tank. I've never had colt corals, but I assume that like most softies they don't like too much light and would do best on the bottom, or in a shady area if you have one. Just my 2 cents....or 5 cents now that we don't have pennies:wink:

I have a old coral life 2x150 + pc fixture over a 75 gallon and have no problem with sps,clams,zoas my other tank is 36x24x12 and have a 6bulb t5 over it and I can't keep anything in it it's too bright. Both are sitting on the legs.

These are double ended. How would I tell if they have UV covers? Is it something the light fixture has built into it? I bought new bulbs last August. That might have been when I started having issues come to think of it.

I only run my lights for 4 hours a day and all the corals are at the bottom of the tank. Hammer and frogspawn are partially covered.

Leanne

The cover glass should be all you need, so make sure the glass is in place.

I'd say that's about half of what they need. I would run them at least 7 hours, supplementing a dawn and dusk with actinic.

Yes, I agree Brad that it isn't long enough, but I never increased it because it looked like the corals were getting too much light. Sometimes they will close up when I turn the lights on and the tissue almost looks swollen on the hammer and the frogspawn and my mushrooms will shrivel right up. I have checked all my other parameters and everything is good so I keep coming back to the lights. I will start increasing the lights and see what happens.

Leanne

And you do have the cover glass installed?

I would think that some sort of reaction to an increase in light would be normal....It may take a few days for the corals to adjust....

Yes, I do have the glass covers installed.

This has been going on for months.