Answers about CFL, HPS, How Much Light...

[ultimatefreak48]

Ok... Im looking into getting an HPS light, 150 watts possibly, but do I absolutely need a ballast... Ive been looking around to see if i can find out if i do or not and I cannot find a clear answer. Can I just plug it into a regular lighting fixture?

[Italiano715]

Ok... Im looking into getting an HPS light, 150 watts possibly, but do I absolutely need a ballast... Ive been looking around to see if i can find out if i do or not and I cannot find a clear answer. Can I just plug it into a regular lighting fixture?

Negative ghost rider.......

[ultimatefreak48]

Negative to being able to plug it into a regular socket or needing a ballast?

[Roughrider]

Ok... Im looking into getting an HPS light, 150 watts possibly, but do I absolutely need a ballast... Ive been looking around to see if i can find out if i do or not and I cannot find a clear answer. Can I just plug it into a regular lighting fixture?

Yeah, you need a ballast. HID lights ("HID" stands for "High Intensity Discharge"...both MH and HPS are HID lights) have to have a very regular energy current flowing into them. The current that flows through a typical outlet fluctuates too much, and that fluctuation will cause the lights to fail.

I know people that really like to DIY everything built their own ballasts, but I think it's kind of kooky for 150w and 250w lights. You can get a full 150w light system with a bulb for about $80-90 shipped...that's not much more than cost of the parts and bulb. A 250w switchable ballast is $150.

If you're thinking of getting a 150w HPS, keep in mind that a dual clamp light CFL setup with 180-190w will set you back less money, is more flexible (you can get daylight CFLs for vegging), has less problems with heat and therefore ventilation, and will put out nearly the same amount of lumens.

[Deejay2163]

Is a 400 watt HPS enough for a 2.5 ft x 4.5 ft room? Would I be better off with a 600 watt HPS instead? Thanks in advance for your reply

[Roughrider]

Short answer--yes. You've got a little over 11 square feet of space, and a 400w HPS puts out 50,000 or so lumens. So you're around 4500 lumens/sq. ft. that's enough.

You may have a problem with the shape of the room, though...if your reflector is getting light out evenly (in equidistant areas, like a circle), the outer parts of your grow area won't see as much light. You'll probably want to rotate your plants frequently, or invest in a light mover. Or, if you want, go for the 600w. More energy and more heat, of course...but more light too.

[1zulu1]

Great thread RR.

Ive been looking at lighting for my 1st grow and was going to go with a 250w cfl, thinking it would be cheaper to run. But after reading your 1st post it seems a 250w HPS would actually be cheaper to run plus the added benifit of more lumens. Only downside is the possible heat with the HPS

[koloradokid]

He definitely helped me more than bomb diggity.

[koloradokid]

roughrider, thank you.

[kwaaluudekid]

I was given a bunch of track lighting that uses CMH (ceramic metal halide) bulbs. the casing for the fixture itself is a spotlight. right now I have a 2 foot x 2 foot area with 4 of these spotlights CMH bulbs on them and they're ready to go into flowering stage at 28" high. I was wondering if this is a decent setup and should I add more light? (I have probably 20 more fixtures and bulbs). Here is some info I found out about the bulb:

GE ConstantColor CMH
CMH20/TC/UVC/U/830/G8.5 (info from box)
3000 kelvin color temp
1650 lumens
LPW efficiency:80-105
color rendering:80-93
color temp:3000-4200

website with info regarding bulbs: http://www.gelightingsolutions.eu/do...H-Dimmable.pdf (go to page 28 for info regarding this bulb. first one in list)


Was also thinking of adding a light or 2 to the sides (these are spotlights after all) to get all-around light, but so far it seems to be going good with just the 4 lights on top. Am hoping to start flowering in a week or two, so my questions are:

1. is this a good bulb for growing? veg? flower?
2. how many lights per sq. ft? (in case grow area increases)


right now only using bagseed, but will have some cuttings soon, so I want my getup as good as can get for the cuttings. Thanks for your help in advance