Ceramic Metal Halide (CMH)

[csharper]

simba, please give me an estimated temperature difference at 12", 400w, hortilux blue vs adv tech cmh *or* where I am running two blues at up to 95 degrees, how high do you think the cmh's would go? .. just your honest estimate; I won't hold you to it

 

[simba]

on the 20-150 watters we want Protected and 4K version..

CSH,
havent tested the actual difference between the two..spd, life, price brought it out of competition. (really should,, ill get my MH ballast back and see,, thatll take me a week+
however that is a full SPD MH so it THROWS heat even moreso than a standard M400U.
many have come in and said small cabs with large watt and have been able to keep cool.. but id say u wont get near those temps with cmh even at 12" with very lil airflow.. between bulb and plants/inplant area

 

[Mr_Micro]

Thanks again for the response Simba!

The CMH does sound very tempting, but I do have one last concern I wanted to ask about before I make the switch from HPS to CMH...

Basically, the box I'm going to be lighting is going to be used for a SOG application. So what I'm really going for is a bunch of small single cola plants in small containers with little to no branches and minimal leaf growth, "bud on a stick" if you will.

So I'm a bit concerned that since CMH bulbs have a lot of light in the blue spectrum that it would encourage my plants to form a lot of branch and leaf growth and make them big and bushy, and that's really not what I want here. Yeild isn't that important to me really, I just want small single cola non-branching "buds on a stick". Because of this I'm a bit more trusting of my HPS, since I know it only puts out usable light in the red spectrum which means big bud growth and very little branch and leaf growth.

So what do you think Simba? Would a CMH still be right for me in this small SOG application, or is the full spectrum light that the CMH puts out going to put my plants at risk of having lots of branching and leaf growth and kill that "bud on a stick" style plant that I want?

 

[Guest]

Mr. Micro: I think the CMH would be right for any application. You WANT leaves and branches and with short distanced internode spacing. You can do SOG and maintain only the needed foliage.

I think you should let the light do it's job and you do yours (ie. pruning, SOG, LST, etc...)

 

[Mr_Micro]

Hmm... good point, although I do have a pretty strict "no pruning" policy. So I like that a HPS gives me almost nothing in the way of branches and very few leaves, but the internode spacing is a bit larger than I'd like so I've been pondering a CMH.

I'll probably give CMH a try anyway, but I do have my concerns about the blue spectrum causing more branch and leaf growth and less bud growth, thus killing my "bud on a stick" SOG concept.

 

[simba]

mr. micro.. youll see in my posts while back i dont like bush's either.. and recommend Single cola-8 cola D-Dikies... however others are loving there bush's...
it all goes to how long you veg.. for.. the shorter the less chance of bush's///

 

[Guest]

I vegged for about 28 days and I got really bushy plants. I would love to only veg say two weeks and get the same if not better results.

 

[BonsaiBud]

It says "ok for open fixtures" on the jacket, But I could put these in lamp-glass cool tubes with CPVC pipe on the ends. It would replace the 3X50 HPS.

 

[Guest]

From Tuesday:

 

[MPL]

Pruning is made of winsauce.

 

[nightcrawler]

I vegged for about 28 days and I got really bushy plants. I would love to only veg say two weeks and get the same if not better results.

I have some palm tree looking plants, and my other 2 got massively tall. But the palm tree ones are soo nice, im def taking clones from them(if there female)

 

[Guest]

I have some palm tree looking plants, and my other 2 got massively tall. But the palm tree ones are soo nice, im def taking clones from them(if there female)

That's awesome. Well, I had to do some pruning so to get the effect you describe as a palm tree. I like the fact that they are bushy. I felt that it accelerated the vegging process and I got rid of leaves as I got closer to week 2 of 12/12. Kind of a sinusoidal graph:

 

[nightcrawler]

Hey everyone, since im using CMH i thought maybe i should also post here....

Plant leaves feel dry

2 people have said it

They look green and abit yellowy(on the outside of the fan leaves)

They also have some browning spots on it.

Ive been watering about every 3 days.

Under a 400 W Philips CMH

5 gallon buckets



Thanks

 

[simba]

MPL, the timer i did have a quick idea and made a Cheapo DIYed one but its not reliable.(if the power spikes or dips it shortens or lengthens the time dramatically, it ran on AC 120V for ease but that caused the power to affect timing..
they will have one coming next Friday that will go to 20 minutes with options..

 

[Guest]

Simba - I have read every post youve made and you have stated a few times that you have friends who have made the change from 1kw to 4oow cmh's and are happy.

A 1kw hps has 145,000 lumen output. A 400w cmh has 34900 lumens. Unless the par watts are close to equal, I am just guessing that the results wouldn't even be comparable???

I am not dissing, I really would like to switch to cmh once the higher wattage bulbs come out. In the meantime I am using 600's over 3x3 tables and would love to know if I could switch out to 400's and get comparable results. I have the ballasts for 400's, but they are just sitting in storage.

Thanks Simba!

 

[PurplePotion]

Of course a 400W lamp isn't going to produce like a 1K.. To make this logical, what simba is saying is that CMH will outperform & out-produce an equal wattage HPS.

Therefore, if you have 2 1Ks, and want to switch to CMH, you'd be replacing your 2 1K lamps with 4 or 5 400W CMH lamps to benefit from the switch.

 

[Guest]

Purple - I got that much. But the added cost of hoods, ballasts, etc seems to defeat the purpose.

My point is that 1kw's have deeper penetration and cover a wider area if necessary. But I use a 1kw or a 600w pretty much equally with only a slight loss in yield. My exact area per 1kw or 600w is 39in x 39in.

Will a 400w cmh cover a 39in x 39in area as well as a 600w - even though it has less lumens?

Trust me - I am seriously interested, not trolling.

 

[nightcrawler]

i have 4 plants going under a 400w CMH, inside 5 gallon buckets, and there looking nice, my first grow so its not the best but im more then happy with it, and the light is only 8 inches from the top of the plant.

BTW my area is about 3.5 feet x 3.5feet(shower)

 

[Guest]

nightcrawler - nice. I am thinking 16 3gal pots under one 400w cmh... jog style.

 

[PurplePotion]

strainwhore- Can't answer your question. I'm actually in process of setting up a new one. Have a DR120 tent, and will be using a 400W CMH as well as a 600W HPS side-by-side overtop of my flood table. Both are in SuperSun2 hoods with an 8" Vortex cooling them (overkill, I know .. my style haha).

Give me a couple months and I'll let you know all of the differences between the two sides.. I'm just hoping for a bunch of fat single colas Good luck.