corals closing up after MH bulb change

[eleyan]

I have 2x175W MH bulbs + 2x55w actenic PCs on my 72G. I used to have a no name 13K bulb (Catalina I think) that came with the retro kit. It was actually more yellow than white. It looked more like 6,500K really. One of the bulbs burnt out and I ended up getting 2 new 15K coralvues. I like the color much better than before. I put them in last night and today most of the corals (especially the ones place higher near the lights) are closed up. The zoos and frogspawn which are on the bottom don't seem botherd though. Is this normal after changing the color spectrum. Both old and new bulbs are 175W, the only different is the color??? and if so how long does in normally last?

[eleyan]

Here are some before and after shots. The Kolt actually closed even more by the end of the day:

[witecap4u]

How long have you had the new lights on? I'd give it a day or two and see what happens.

BTW, you should also run your new lights for a couple hrs less each day for a week or two to give your corals time to adjust to the higer output of new lights.

cs

[eleyan]

three days later and they are still closed. I noticed that they close even more by the end of the day after the MHs have been on for about 6 hrs. Today, I'm not turning on the MHs all togather, just the actenics, to see if they look better when I get back home. I might but back the one old bulb that was still working with one of the new ones to see if that helps with the reansition. Any Ideas?

[Polkster13]

Can you open the hood and place the lights higher off the water? It sounds like the corals may be in shock. You could try using just one bulb and then adding the second one later (as in a couple of weeks). That way you stagger the times you will make bulb replacements which should help the corals acclimate to the new bulbs.

A quick tip. Use a Marks-a-lot (permanent marker) and write the date on bulb when it is replaced. That way you will know how long it has been in there and give you an idea of when it needs to be changed.