Photo period when switching to MH

[Dez]

I would either go to Home Depot and buy some window screen material and put a few sheets over the tank to "shade" the light a bit. Then every week take a sheet off so that the light is getting more intense by the week.

Another option is to run your lights 1/2 hour on, one hour off, 1/2 hour on, one hour off and then gradually "meld" the photoperiod into one long photoperiod over the course of a few weeks. (This is how I did it when switching from 150 watt halides to 250 watts) It just takes more fooling around with the timer. I was too lazy to go buy screen material and rig it so that it would "sit" over the tank and under the lights.

Hope this helps.