Switching to metal halide from PC

[trapper]

I am switching from 96 w CF lighting on a 10 gallon to a 175 w metal halide ( 10k ).

 

Is there an acclimation period needed? What do you recommend?

 

Thanks.

[sheen]

Definitely. That's a significant change and you will need to cover the tank with some sort of light shield, and move the lights as far away from the tank as possible on the first day. Start out on half the photoperiod you wish to have at the end and bump it up slowly depending on coral reaction. What kind of corals do you have?

 

If you could get multiple sheets of lighting filter and remove a sheet every few days that would work as well. At the same time lowering the light a couple of inches. Adjust the photoperiod slowly as well.

 

If the corals show mild amounts of lightening in color, that is perfectly normal and it is inevitable as your goal is to provide them more light anyway, as opposed to having them stay with their original lighting.

[JGard]

I did the same thing. I started by hanging the pendant about 12" off the water for the first two days and left it on for only 4-5 hours per day. Then I lowered it to about 7" and left it on my normal schedule of 12 hours per day, and things have been fine.

[BREAD]

I found in easier to leave the light on for 3 hours for the first day then 4 hours the next day then 5 hours and so on until you get to your desired photoperiod. This is the method I used and everything is fine, I didn't use any window screen or didn't have to adjust the height.