Ceramic Metal Halide Bulbs

[Old Yeller]

Who here uses Philips CMH Bulbs?
I've been using a 400W for a few months with good results & would like to hear from some more experienced growers what they think.
I've heard that you need to add silica to your nute schedule when using these lights for some reason. Also some people will use them in the beggining of flower & switch back to HPS to finish.
Any thoughts?
OY

 

[jdubz206]

Who here uses Philips CMH Bulbs?
I've been using a 400W for a few months with good results & would like to hear from some more experienced growers what they think.
I've heard that you need to add silica to your nute schedule when using these lights for some reason. Also some people will use them in the beggining of flower & switch back to HPS to finish.
Any thoughts?
OY

I use 2 x 400w philips cmh in veg...they work amazing in veg...i didn't have great results in flower..ran them for a couple of harvests, then tried a hortilux super hps bulb...hps worked much better for my garden...

 

[Old Yeller]

jdubz206 - Can you tell me the difference in your plants/buds under cmh vs hps?
I'm using a 250W Hortilux MH for my final veg & was debating on switching to a cmh. Trouble is i'm using a digital ballast (Galaxy) & would need to buy another hps ballast in order to use these bulbs.

 

[jdubz206]

jdubz206 - Can you tell me the difference in your plants/buds under cmh vs hps?
I'm using a 250W Hortilux MH for my final veg & was debating on switching to a cmh. Trouble is i'm using a digital ballast (Galaxy) & would need to buy another hps ballast in order to use these bulbs.

sure...the difference was the hps produced more, can't remember the difference at this exact moment (it was a while ago), but i did a side by side with the same strain and the hps produced more (at least 25% more) and also denser buds...if you can step it up to a 600 watt hps in flower, you'll notice a huge difference, especially with trichome production..

honestly, the only reason i've been using cmh is because i had the 400 watt magnetic hps ballasts lying to begin with...if i would've had to purchase new equipment, i would've grabbed a 400 watt digital ballast and a hortilux blue bulb ..i'm sure within the next year i'll be grabbing a 1000 watt MH setup and a hortilux blue..that will replace the current 400w cmh's...then i'll most likely use those ballasts with hps bulbs for side lighting in my flower room...i think the hortilux blue bulbs kick ass...the plants go crazy under em

 

[Old Yeller]

Thanks for the reply! I've got 9 plants flowering under a 400 cmh now, but i think i'll switch to my hortilux hps next week to finish flowering them. I gotta say that they all look great so far under the cmh, but i've never taken any plant all the way thru cmh yet.
The 250w hortilux mh i have now is rated at 4000K - are the "blues" different? I'm not sure they make the blues for 250W.

 

[highroller]

I've used them as well. Although the plants respond very well to them in veg and flower, I would have to say the yields were a bit smaller when used to completion of flower. The plants seemed to stay greener longer and produce a tad more leafy growth. Switching back to HPS for the final 2 weeks of flower is a pretty good idea...one that I hadn't thought of. Thanks, I'm gonna try it.

 

[jdubz206]

Thanks for the reply! I've got 9 plants flowering under a 400 cmh now, but i think i'll switch to my hortilux hps next week to finish flowering them. I gotta say that they all look great so far under the cmh, but i've never taken any plant all the way thru cmh yet.
The 250w hortilux mh i have now is rated at 4000K - are the "blues" different? I'm not sure they make the blues for 250W.

the blue's come in 250 and have a great spectrum...i'm not sure of the kelvin rating

here's the brochure:

highroller - i noticed more leafy growth as well...i love em in veg though...i high recommend these bulbs for anyone who has a 400 watt magnetic hps ballast laying around...the way i started was real small...t8 fluorescent bulbs in veg and a 400 watt hps..then i bought a used 400w hps ballast for $100 and threw a cmh in...next i tried 2 x 400w hps and i liked it better...then i got a 600w hps ballast and stopped the t8 vegging...used the 400 watt cmh in veg and it's really working out great. once i got more lights in flower i needed more room to veg...so i threw a cmh in the other 400 watt ballast and now i'm getting really fast growth..lovin it..i was thinking of buying a 400w MH or 1000w MH ballast..then i started thinking of a 4' 8 bulb t5 system and finally i decided since i had a hps ballast layin around, i should just use that...least amount of $$$ to invest and the money i didn't spend can be used for more lights in flower :banana:

 

[OSwiZzLe]

i used the CMH bulbs 3 times....the last run in growzilla dual hood 800 watts of CMH....dude it was horrible...one 600 watt hps tore up that set up ...side up side same strain....those bulbs are junk...use the Horti Blues for Veg and whatever HPS for flowering....the only upside is the nugs grown under the CMH have more smell and flavor...but not anything to write home about ..

 

[eyes]

hps for bud density and mh for resin content.add some uv bulbs to the mix with you hps for ultraviolet wavelengths.or just add a mh to the mix with your hps mix up the spectrums.

 

[Zedlepplin]

I use full spectrum cfl's for clones, seedlings and CMH for everything else. I the only blue / red lights I have now are some leftover cfl's that I use for spotlights.. and supplemental lighting.
I am having great results, but I have a small grow area.

You can put the light closer to the plants with CMH because they throw less heat.

 

[Old Yeller]

jdubz206 - Just checked out your link - looks like i got the regular MH @4000K - The blues run at 6500K & for $100 they better be the shite! It looks like it might be a good alternative over a cmh for veg (i won't have to buy another 250W hps ballast) - hope they run OK on digital ballasts...
I still think i'll use my 400W cmh for beginning flower, then switch to hps half way thru.
eyes - you're totally right about mixing spectrums - i'm still toying with the idea of adding a UV-B reptile light in flower to see what happens.
oswizzle - Thanks for your input - personally, i don't think they're "junk" - you just have to use them selectively - are you in dirt or hydro?

 

[Cali smoke]

I use cmh, I want to grow my plants under the same spectrum they'd be if they were outdoors. I get healthier plants growing under cmh and silica helps strengthen the branches. I recommend LST under them though since light penetration isn't that good.

 

[halitzor]

I dont know where you guys are getting your info but CMH has more red and orange in the full spectrum it puts out than HPS does. The best is to combine HPS and CMH into a setup, mixing the light produces awesome results.

Check this baby out, this is not even 1 month flowering under 400cmh and 600hps.

DJ short blueberry