Photo period when switching to MH

[JenniferL]

I bumped it back a bit to be safe. Does one hour on, one hour off, one on sound okay? I have a torch coral, open brain, gsp, xenia, toad stool, and a BTA. They are all on or near the sand bed at the moment.

[Dez]

I would stick to 1/2 hour on 1 hour off just to be safe because your corals really didn't have too much light before compared to your new light/new bulbs. I know it's a pain, but I'd like to error more on the safe side.

[Madreefer]

I was told that turning mh off and on frequently like that is hard on the bulbs as well as the ballasts. Someone correct me if i'm wrong please. I would have them turn on for just a couple of hours where you know it will be the middle of your lighting period, increase the time by 20 more minutes each day until you reach your actual time they will be on every day. 10 minutes earlier and 10 minutes later each day. Most people on run mh's 6-8 hours per day. Also think that it will stress your fish out if the lights keep going off and on. Everyday when my mh's turn on there seems to be a burst of energy with the fish for a couple of seconds (freak out). And yes heat will be a bit of a concern during summer months.

[DiverDude]

I'd try and get your lights higher up for a while. If that's not possible then the previously mentioned layers of screen should work in a pinch.If you raise them, drop them an inch or so every week until they are where you want to leave them.

Dropping an hour from your photoperiod may not be a bad idea either. However I certainly would not switch them on and off. Remember you are trying to simulate a slice of ocean in your house and in the wild, the sun does not pop up and down every few hours. Will it hurt the fish ? Probably not but I don't think it's good for the lights/bulbs.