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ambr0sia
Member
How important exactly is the socket cord length? I've heard alot of folks mention that anything above 6-8ft is Bad News Bears for CMH, which is quite the bummer since the CoolTube I picked up specifically to house a CMH has a 15ft cord from the socket to the ballast...
Think it's a safe gamble? What're the consequences if the cord is too long? Does it just not ignite?
Thanks!
Think it's a safe gamble? What're the consequences if the cord is too long? Does it just not ignite?
Thanks!
S
Seismic
I have mine running on a sun system ballast and cooltube which also has a 15ft cord, and it fires no prob.
ambr0sia
Member
Ahh, great to hear - That definitely gives me hope. I can't find any documentation on the Phillips site relating to cord length; Anyone care to share where this info came from?
Any folks out there have experience using CMH with Hydrofarm's 400W XtraSun magnetic ballast by chance?
I think it goes to the firing range of the igniter. The igniters in the ballasts I use (Advance 250w's) have a firing range of two feet, but it will fire at longer ranges. I used 12 AWG wire extension cords, but 14 AWG should do ok too (the thicker the wire the less resistance the igniter has to overcome) for about 10' of total cord length for each light.
Namaste, mess
Namaste, mess
I went 15' on a Husky extension cord, $8.95 home depot,turned into lamp cord
16/3 kicked right on.
16/3 kicked right on.
Hey guys and gals. I have watched this thread over time and have come back to it and others like it. with a few comments. First a short bit of background. I have used CMH bulbs at 400w since early 2006. I have used a 400w MH 400w hps 250w hps 600w hps and flouros. I'm not a professional and if you search my earlier posts you can see i had a shaky start. You can also see i can grow some very nice bud now. Just like everyone else it all takes time and trial and error and learning from your mistakes. But it's best to learn from the mistakes or the progress of others. So what I have found with these bulbs every time is that they produce crazy roots, in cloning or vegging. The plants also Love this bulb during the first 1-3 weeks of 12/12 then it's back to the 600w hps. Now how long you use it in 12/12 is strain dependent but it effects the stretch, by keeping it in check and adding to the thickness of the branches. If you have a weak branch strain this bulb helps the plant bulk up it's branches. Also as mentioned at different times the heat output of a CMH has come up i hae found it's almost all upwards, so for most open reflector setups its very good. Obviously a cool tube is no problem. I do understand many people grow in confined spaces and have limited cooling. PLEASE take all of this as a personal observation. I don't have a degree or pages full of hard evidence. Just another dude on the internet with babble to add. So I hope this helps someone who is using these bulbs, I know I like them.
F gandalf
here is a few shots of c99 x a11 grown as i described above
F gandalf
here is a few shots of c99 x a11 grown as i described above
FGandalf, awesome pics and great observations. Could you elaborate a little more on why you believe:
"The plants also Love this bulb during the first 1-3 weeks of 12/12 then it's back to the 600w hps."
I'd like to hear your reasoning as I currently use both 600W HPS bulbs and 400W CMH. I am close to finishing my first grow with CMH and haven't yet decided which is the clear winner for quality, dense buds, stretch and trich production.
"The plants also Love this bulb during the first 1-3 weeks of 12/12 then it's back to the 600w hps."
I'd like to hear your reasoning as I currently use both 600W HPS bulbs and 400W CMH. I am close to finishing my first grow with CMH and haven't yet decided which is the clear winner for quality, dense buds, stretch and trich production.
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simba
Sleeping Dragon
GM, that is a hard one to answer..
there is a few reasons why they not going to, they where working on them but went a different route.
1. saftey when a 400 MH blows it just blows about 1-2 grams of quartz thin glass in Many Many pieces..
when a 400 CMH blows about 4-7 grams of alumi-ceramic goes flying like missile generally 1-2 pieces. (and retains the heat in the alum-ceramic arc tube)
Mh and cmh blow at end of life (when pushed past Proper replacement time IE 95% rated Life Hours)
cmh does have a tendency to blow during Life aswell (very rare but happens) because the Seals fail and then its got a lil hole the pressure comes out AKA rocket..
(hence one big reason why we tought the philips CMH over any other brand EVER (unless something better comes along)
(take a look on adv tech site cmh fact at bottom Shows what i be talking about..)
now think a 600 or 1kw cmh pressures.. its just not safe.. in any fixture.. (it would need Ballistic rated glass (this i know i have seen a 700w cmh blow and oh god i thought i was gonna die)
now to the good news.
rather than waiting for higher wattage's just wait for more effeciant lower wattages.. IE philips has new cmhs that have just come out (not good for horti, there spd is more yellow green)
in realilty though i do not see the need for 600s' or 1kws any more..
after seeing so many setups that have gone to 400 cmh and my personal experience i dont see the need for 600's or 1kwrs..
i have seen rooms that needed AC with many 600's -1kwrs that have switched to 400 CMH (using more lamps and equal to greater cmh wattage) and rooms are cooler without the ac working so hard (used air cooled hoods they had for there other lamps)
my biggest prob besides there spd with 600+ watt'ers are they emit allot of heat and its super PITA to handle that extra heat.
i wont deny 600+ have penetration power but they also need to be hung Higher..
i will say impho with cmh the grow style oughta change a bit..
with hps we all veg like crazy and grow bush's (primarily) and with cmh you veg less and have xmass tree looking plants (u can grow big bush's with cmh but you should use Multi lamps at that point so there are no shadows.)
(last note some peeps i know that have masterd cmh use the same grow size with just a few more plants, they veg less and have 1-3 colas each and produce more than they did with there Bushes (total harvest)
(also in a shorter amount of time since no long veg length)
Divenosa Well what i mean is that many people have plants that have a big stretch when you go from using a mh in veg to hps in bud. In tight spaces this can be an issue for some more then others. But it's not so with the cmh. Also i mentioned above that the plants seem to be much sturdier then when grown under a hps in veg or a mh in veg. So what i found was it kept my plants a bit more compact and sturdier by using the cmh and also running it into my bloom cycle 12/12 for 1-3 weeks. (strain dependent) then i switched over to a 600w hps and finish 12/12 with that. Alot of his was because i was tryig so many different things. 
Literally on the verge of ordering mine, but I'm being indecisive at the 11th hour, and don't know whether to get 250W or 400W!
I'm basically in a small BudBox, 6sqft, 1m (40") high. Way oversized fan for the space. Extraction through top of chamber, no aircooled hood (yet), but fans blowing around and across the bulb too.
The 250W would give around 41W/sqft, and the 400W around 66W/sqft - one feels too few, one feels too many. One minute I'm leaning towards the 250W as I'll definately get more g/W, but if I could justify the extra electricity, and keep it cool, the 400W would surely yield more? Just not 60% more!
Any advice on which option to go for would be hugely appreciated. Anyone got experience of using a 400W CMH with just 40" or so of height?
Many thanks!
I'm basically in a small BudBox, 6sqft, 1m (40") high. Way oversized fan for the space. Extraction through top of chamber, no aircooled hood (yet), but fans blowing around and across the bulb too.
The 250W would give around 41W/sqft, and the 400W around 66W/sqft - one feels too few, one feels too many. One minute I'm leaning towards the 250W as I'll definately get more g/W, but if I could justify the extra electricity, and keep it cool, the 400W would surely yield more? Just not 60% more!
Any advice on which option to go for would be hugely appreciated. Anyone got experience of using a 400W CMH with just 40" or so of height?
Many thanks!
Are multiple lights an option? Say, three 100w's or two 150's? Height would be slightly less of a concern. You can get your lights closer and get a better spread if your cab is particularly narrow.
Namaste, mess
Are multiple lights an option? Say, three 100w's or two 150's? Height would be slightly less of a concern. You can get your lights closer and get a better spread if your cab is particularly narrow.
Namaste, mess
TBH I'm not sure what to do!
The flowering tent is exactly square, 75cm x 75cm.
I know potentially two 150 watters are optimal, the most efficient W/sqft ratio, less distance required between tops and lamps, a better spread of lumens - in fact, until I discovered faults with my existing ballast(s), 2x150W HPS was my lighting for the tent.
I'm swaying away from 2 lamps now though, partly due to cost (would need two new sets of control gear, and two bulbs), and partly because I'm feeling the simplicity of only having to hang and adjust one lamp.
I've been trying to discover the best hood design for a square space too. I quite like the Ultralite style 'octagonal' reflector, but that particular model looks like it wastes too much light by not having a v-shaped reflector above the bulb.
Any other thoughts/input appreciated!
HawaiianPunch
Member
How much would it cost to purchase a 250watt with a good ballast? Could anyone point me in a good direction? Sorry all, didn't want to scroll through 170+ posts
Look in the second post on the thread. Go to the Advanced Tech Lighting website linked there. It's about $100 roughly, all available on that site.
HawaiianPunch
Member
Okay, thanks, I dunno why I missed that. I've actually seen that site before... So if I buy a light and ballast from this site, is it ready to go? Just plug in the wall? Do I have to get something special or wire stuff or anything? Ready to go?
