Have you thought about buying a dual ballast?

I mean, it may save you money in the end, because when you can afford (both financially and temperature...ly)to put in another light, you'll already have a ballast for it.
graph Reviewed by graph on . Ballast question Hi all I got a 400W MH lamp with a ballast. Also have a 600W HPS for flowering, also with a ballast. Problem is, I'm vegging with the 400W but the weather is just too hot. I can manage temps with difficulty. If the weather doesnt change soon, I will have major problems with flowering once I switch to 600HPS. What I want to do is to get a 400W HPS bulb for flowering, I'll use the 600W exclusively in winter. Question is, can a 400W HPS bulb be safely connected to the ballast of a 400W Rating: 5