Acclimating tank to new MH lights

[Trey302]

I had some questions regarding the best way to acclimate corals when switching from PC to MH lights. My tank is a 72 bow that currently has 4 65w PC's. This week I'll be changing the lighting to 2 150w 10K MH and 4 54w T5HO. The tank contains softies and LPS.(torch, frogspawn, galaxea, mushrooms, xenia, open brain & sinularia)

My question is how should I go about acclimating everything to the new lights? Keep in mind the light will be hanging from the ceiling so the height of the light is very easily changed. Currently my actinics are on from 10am to 11pm and the 10K's are on from 12 to 7. Should I try and keep a similar light schedule, just have the lights much higher above the tank and lower them over time? Or would it be better to just cut the light cycle back and just build it back up slowly?

I would rather keep the same schedule and just adjust the height of the light over time if this is a good option. If this would work okay, does anyone have a good idea of how high I should have the light over the tank to start with, and how often to lower it?

Sorry for all the questions but any help is greatly appreciated. TIA

[jer77]

It takes a rather long time to get the corals completely acclimtated to the new light. I'd say it will take about a month until the lights will be in their final position. I would raise them to about 18'' above the water and for the begining lower their photoperiod. Having the photoperiod less is probably the best way to acclimate corals to brighter lighting. I'd lower the MH's to about 4-6 hrs a day for the first week, then about 6 hrs for 2 weeks, then 7-8 for the last week. I wouldn't worry too much about the soft corals, but the LPS may bleach if not properly acclimated. If anywhere through the process you notice the colors of your corals whitening or looking washed out then raise the lights a few inches. I'd say the height that you'd want the lights to be at the end is 6-12''.

[teena]

i put three layers of screen over the top, then pulled one layer off a week,

[Henry Bowman]

I agree with jer77. If you find that anything is starting to bleach you can put a couple layers of window screen over that area of the tank and stop lowering the light and maintain the photoperiod. Then after a few days, you can remove a layer of the screen, then wait a few days and remove another etc....

PS Teena you must have posted while I was typing.... Good idea.

[ReefForBrains]

I second the screen method, works well.

Just beware of heat issues if screen is too close or MH are hung to low.

[sammyfish]

Do you mean like a house widow screen? Can you get them at HD or do you use screens from your house?

[teena]

i got mine at HD, they have it in a roll, i also got two wooding sticks from there, i cut the screen to fit my tank, then cut the two sticks & stapeled the bottom screen to the sticks, not the top two, that way you can pull those off as needed, i also found the screen was sagging in some places so i put egg create under it, even after my time was up for the screen i left the egg creat up there to stop the salt from getting on my lights, heres a pic off the egg create, also @ HD, you cut it to size, with wire cutters, its about $12 a sheet,

[teena]

[sammyfish]

That's a good idea. Thanks.