Metal halide acclimation

[Hpimichael02]

Good evening AC,

I have found a way to hook up my new MH fixture to my 55G tank, all my corals are glued in place and hard to move down, do I need an acclimation period moving from 4 t5 to 400 watts of 2 150 Mh and 2 96 watt PC? Could i keep my photo period to 4 hours for a couple weeks?

[Rollins4Miles]

Yes, you should acclimate the corals to the news lights. The addition of the halides may have an adverse effect on some of the corals. General rule of thumb, if moving coral into less light, than you don't need to acclimate - if moving into more light (or in this case bringing more light to the coral) you need to acclimate. I had to do this when I switched from T5s to a MH/T5 combo.

All you need to do is go to a home improvement store, pick up some fiberglass window screening, cut to size, and simply place it on top of the aquarium. I use chopsticks as frames/supports so the screens don't fall into the water. This will filter out enough light as to not damage/shock your corals. You can put two or three pieces under each MH and remove one piece about every week.

I hope that was explained clear enough. Best of luck!!

P.s. Photoperiod isn't as applicable as you may think. Even lowering it to 4hrs, you're still going to have that increase in intensity which is what creates the damage, not necessarily the duration.

[Dave66]

What I would do is to raise the light higher, say two feet from the water surface, as less of the halide light would hit the tank, since the light would spread out. Over the next few weeks, you can slowly move the fixture closer, perhaps an inch or so a week, until the fixture is placed in in its final height.

Your corals will improve in growth and color with that halide light, since halides approximate height of the day sunlight over the tropical reefs better.

Dave

[hockeyhead019]

I've read of people putting window screening over the tank (the black stuff since it eats up more light) and then removing that and putting egg crate over, just to break up the intensity

Also you should start with the coral at the bottom of the tank and then move it upwards accordingly, however I know people don't like this because it can stress the corals.

Dave's idea is very good if you have the ability to adjust how close your lighting is to your tank