400w mh? or 400w hps?

Hey guys need some advice what would be better n more cheap on the electric bill???

,,,,,either way its 400W so its gonna be the same on the power bill. Either get both....and a switchable ballast....or get an enhanced spectrum HPS that has some blue spectrum in it.

What work better throughout the grow?

If you had to choose one or the other, HPS. You'll get stretchier plants in veg but denser buds in flower. Ideally you get digital ballast and one of each bulb and have perfect light the whole way.

How far away should I put the light?

As close as you can get it.

Put the back of your hand facing the bulb over the plants and when it gets uncomfortable then it's too close.

With the right fixture and ventilation you can get them this close:

ULMResearch said:

As close as you can get it.

Put the back of your hand facing the bulb over the plants and when it gets uncomfortable then it's too close.

With the right fixture and ventilation you can get them this close:

Click to expand...

You're supposed to be able to hold it there 5 minutes without discomfort, hid lights will burn your hand and your plants if you hold them that close for too long.

I could have held mine there all day really, but I don't like getting skin cancer!

But yer right, wait a minute or two for it to build up before rushing to lower the lights.

I think with my air cooled hood i could literally all day, no worries about skin cancer Ive got melanin lol.

I keep mine about 6 inches away from tops. Some ppl can get them closer, if you have a regular hood u will want a foot or foot 1/2 for standard reflectors on a 400w.

If heat is an issue get that air-cooled shit. i swear, best investment, everyone will agree that an air-cooled hood will solve most of your heat issues.