Acclimating new light fixture?

[Cash]

Ok I plan to get my new light fixture within the next 2 weeks. I am replacing a 4 T-5 fixture with a 4-T5's and 2 250Mh fixture. I dont want to shock the corals. Looking for some good tips on how to acclimate in the new light. I will be using the same T5 bulbs I am currently using.
Thanks

[tazzy695]

go down to lowes or hd and get some some what open window screen and put several layers under the mh to dim it down take a layer off a week till you have none left and you are done

[ReeferRob]

What Tazzy is trying to say is, get some fiber glass screen. Put up probably four layers over the tank, removing one each week. By four weeks everything should be gravy.

One thing, get some actual MH keepers advice first. I used this method when I changed over from PC to T5 like 5 years ago and worked fine. But not sure if this method is preferred with MH lights and the excessive heat the crank out.

[evilc66]

This works fine, even with MH. The fiberglass screen doesn't care about the MH heat.

[tazzy695]

only difference is you have to keep a little more distance from the mh as I just dropped from mh to t5 alone to save on the power bill

also is this going to be in an enclosed canopy if so make sure you have fans and dont bolt the reflectors directly to the wood keep at least and inch or two to prevent the wood from burning

[Cash]

No I dont run a canopy on my tank

[tazzy695]

so is the 4x t5 and 2x mh going to be one fixture or 2 t5 fixtures and 2 mh pendants hanging ??

if so it is a good idea to keep the mh about 6" higher then the t5s

[Sir Patrick]

This fixture gonna be on legs, or hang over the tank?

If its gonna hang- hang it very high, and lower it little by little, till its at the height you like. Great way to aclimate a new MH light set up.

The layered screen works well too!

[Cash]

This will be a all in one fixture. Leg mounted on the tank. So the T5's and Mh will have to be the same height.

[tazzy695]

Ahh ok just try to shade the halides not the t5s as to show smaller increases of light withe dropping down

[Limpit]

I would just shade the whole thing. With the increased Parr value that the halides will be giving off it will make up for any loss for your existing T5's that would have be shaded. Corals with too much light in captive system will bleach, too little light will brown out for a while but can be brought back with an increase in light.