Metal Halide vs CFL

I have vegged using CFL's, and other times with HPS lights. I have found CFL's make for a ton more nodes, and closer spacing (with the mother/clones I have now), but growth is overall far slower than with HPS. HPS is faster growth but seems to produce less nodes with greater spacing.

I have never used MH lighting before, and I am assuming that switching to MH for veg will combine the best of both CFL (short and prolific node spacing) and HPS (lumens and penetration) when vegging.

Is there anyone who has experience switching from vegging with CFL to vegging with MH who can enlighten me as to what to expect.

I am happy with how the CFL's are working for me except for speed, and incorporating another hot lamp and it's associated issues into my setup will require a major re-design and alteration of my grow area, so any useful info anyone has will be greatly appreciated.

expect heat problems

besides that, mh, imho, is the superior lamp for growing...
yeah, hps gets you tight nugs and fast yields, but at a lack of potency. thats just MY opinion tho, i expect 3 dozen people to correct me as soon as this post hits.
whats the reason i like MH so much?
UVB radiation... (it forces the plant to grow more trichs)

IAm5toned said:

expect heat problems

besides that, mh, imho, is the superior lamp for growing...
yeah, hps gets you tight nugs and fast yields, but at a lack of potency. thats just MY opinion tho, i expect 3 dozen people to correct me as soon as this post hits.
whats the reason i like MH so much?
UVB radiation... (it forces the plant to grow more trichs)

Click to expand...

Thanks for the reply, I never actually thought about the UVB differences between MH and HPS, or CFL for that matter. Do all 3 radiate UVB of differing strengths or is UVB absent in one or both? Is the heat created by a MH similar to that of an HPS?

they all radiate UVB, any discharge lamp does. (a gaseous element lamp, aka, floro, hid, or cfl is considered a discharge lamp)
it just so happens that the unique combination of elements within the metal halide lamp, emits significantly more UVB when they flouresce, as compared to other types of lamps.
the holy grail of lamps, is the sulphur based plasma lamp.... but you cant get those, yet. another 2 years.

bump bump bump

CFL's are top of the line for early stage development. Rarely and more like never, did i burn plants with a CFL in the seedling stage or have any issues with heat stress. MH do have some issues with heat and can be quite troublesome in early growth. I always vegged mine under CFLs to 6 inches(average) and then moved them into a veg chamber under a MH, i found that at that point plant was vigorous enough to withstand the power of the MH. I don't know what kind of area you are working with, but i think your best bet would be to try and evolve your grow into a SOG format and take advantage of both CFLs and MH. but if you can't do that, definitely invest in a MH light, it speeds up growth so much more and the buds always look frosty with em.

Justcallmedude said:

CFL's are top of the line for early stage development. Rarely and more like never, did i burn plants with a CFL in the seedling stage or have any issues with heat stress. MH do have some issues with heat and can be quite troublesome in early growth. I always vegged mine under CFLs to 6 inches(average) and then moved them into a veg chamber under a MH, i found that at that point plant was vigorous enough to withstand the power of the MH. I don't know what kind of area you are working with, but i think your best bet would be to try and evolve your grow into a SOG format and take advantage of both CFLs and MH. but if you can't do that, definitely invest in a MH light, it speeds up growth so much more and the buds always look frosty with em.

Click to expand...

Thanks for the reply. Do you find that MH helps with keeping node spacing short?

Not in early stage development, I have had a really hard time finding correct spacing and had heat issues that would lead to heat stress on my seedlings and (typically) they wold stretch. I would never germ a seed under anything but CFLs or Flouros. But like I said once you see your plants becoming more vigorous in growth MH is the way to go for the bulk of vegging.

IAm5toned said:

expect heat problems

besides that, mh, imho, is the superior lamp for growing...
yeah, hps gets you tight nugs and fast yields, but at a lack of potency. thats just MY opinion tho, i expect 3 dozen people to correct me as soon as this post hits.
whats the reason i like MH so much?
UVB radiation... (it forces the plant to grow more trichs)

Click to expand...

Im glad you said that because I am veggin and flowering under a MH. How many plants do u think I can effectively grow under 1 400w MH?( Full flowering sixze)

Justcallmedude said:

Not in early stage development, I have had a really hard time finding correct spacing and had heat issues that would lead to heat stress on my seedlings and (typically) they wold stretch. I would never germ a seed under anything but CFLs or Flouros. But like I said once you see your plants becoming more vigorous in growth MH is the way to go for the bulk of vegging.

Click to expand...

I began mine under MH and it was fine, with the dome over the seedling, it created great humidity. just keep it like 3 ft away for first couple weeks. then move in 1 ft. then 6 inches....u get it. NEVER CLOSER THAN 12" REGARDLESS. Its way too hot.

StonedBlownSkiller said:

Im glad you said that because I am veggin and flowering under a MH. How many plants do u think I can effectively grow under 1 400w MH?( Full flowering sixze)

Click to expand...

I have 12 full sized flowered plants under a 400watt MH right now, some topped too. so you should be able to do that at least....most people will say around 8 though ...50watt per plant i think...so 50x8 = 400watts needed

cfls are balanced in all spectrums wich is why they are good for all stages...but you indicate useing a hps for veg...lol...hps is dominate in the red spectrum wich mimics the fall sun light and is much more appropreate for flower then a cfl...cfls do so well in veg because they reside in mostly blue spectrums more so then red. I use a 400 watt mh bulb(blue specrum dominate) in veg and then pop them over to 1200 watts of hps in the flower room. heat...no problem...rooms is 9ft by 12 ft with a 465 cfm exhaust fan with carbon filter. that sucks most of it out and then I got me a evaprotive cooler on wheels from home crap hole and modifiyed it to have constant water supply wich drops the temp lower and adds humidity to out dry air....day time its usualy 85.4 deg with a 50% R.H. I cut the cooler at lights out to dry the air to avoid bud rott and night time its 74.3 with a 41%R.H....wha Im seeing and hearing some good things about tho is L.E.D lighting...cheaper to run with very comarable results

Scott187 said:

I have 12 full sized flowered plants under a 400watt MH right now, some topped too. so you should be able to do that at least....most people will say around 8 though ...50watt per plant i think...so 50x8 = 400watts needed

Click to expand...

as I said in first post...mh is a blue spectrum ...mimics spring colors....you could flower with a mh but youll get way beter results by using hps in flower....Ive even heard that mh and hps in the flower room is great if you keep the spectrum leaning to the red side....hps.....cfls are always to the blue side.

1nicegrow said:

as I said in first post...mh is a blue spectrum ...mimics spring colors....you could flower with a mh but youll get way beter results by using hps in flower....Ive even heard that mh and hps in the flower room is great if you keep the spectrum leaning to the red side....hps.....cfls are always to the blue side.

Click to expand...

I use a MH and a few higher watt CFL bulbs that are made for flowering spectrum

I have learned personal that CFL or LEDS do not cut it ! Thats my thoughts and scientific test study i have learned threw the years ! Next couple of months im bumping it up to 600 watt Mh HPS ballest from HTGsupply this time im going to use a cool tube or a inline 4 or 6 inch reflector.

what do you guys think about

sprouting a seedling with CFL then once it pops and grows first set of leaves, move under 250 MH for vegging, then move them under 600w hps for flowering

you guys think this would be the best use of all 3 lights? i already have CFL's, 600w hps and i ordered a 250w mh/hps phantom ballast so i was thinking about using it for vegging my mother plants under the 250w mh