Lighting Dilemma

[klondike4001]

I've got a 24 gallon NC, and I'm upgrading to a 70 Gal. Oceanic over Christmas, I'd like to begin getting the corals and other critters used to the MH lighting that will be over the new tank. The lights I will be getting are a used set with a couple months usage on the bulbs so they are beginging to dim already. I figure it'll be perfect to get everything used to the new lighting with older bulbs.

Now for the problem, I'm not quite sure how high I should keep the lights, or if I should add layers of screen to the top the the tank and remover a layer per week to assist everything in getting used to the light.

Any comments or suggestions would be greatly appreciated.


Thanks,
Jonathan

[Ed]

Just start with the MH on a few hours a day and gradually increase the time over a period of a few weeks. I wouldn't worry about adjusting the height or adding screens.

HTH.

-Ed

[klondike4001]

I'm worried about the 250 being too close to the tank

[Ed]

I've had a 250W Mogul six inches over an 18g tank running about 5 hours a day with no issues (other than heat). As long as it doesn't get splashed, you should be fine. Are yours Mogul or DE? Pendants or retros in a canopy? In addition to shortening the photo period, you could also start the corals lower in the tank and move them up as they become used to the light.

[klondike4001]

As far as I know it's a Mogul, it's a retro. Would I need a UV glass shield. Shorten the photo period with just the MH, yes, but can I supplement the other few hours of the day, w/ power compacts? Do you recommend using the sreen method to lessen the light over the tank for a few weeks?

[Ed]

You do not need a shield if it is a mogul. If it is a DE bulb, then yes, you need a shield. Absolutely supplement with PCs. The corals are used to those. Just start out slowly with the MH, gradually adding time week by week until you get to where you want to be. No, I don't recommend the screen method. Don't think that it is necessary if you shorten the MH photo period. HTH.

[klondike4001]

Ok I've got it over the tank, it's at least 14 in from the highest coral and probably 26in from the zoas on the sand bed, at that height should I worry about coral bleaching? I figure at that height I can let it run for a few more than 2 hours w/o doing any harm, please lmk what you think.

Thanks,
Jonathan

[Ed]

Don't think bleaching from too much light will be a problem. Might start out at 4 hours and increase it an hour each week until you get where you want to be.