What's new
  • Please note members who been with us for more than 10 years have been upgraded to "Veteran" status and will receive exclusive benefits. If you wish to find out more about this or support IcMag and get same benefits, check this thread here.
  • Important notice: ICMag's T.O.U. has been updated. Please review it here. For your convenience, it is also available in the main forum menu, under 'Quick Links"!

how many add days going from hps to cmh

zachrockbadenof

Well-known member
Veteran
we normally are using 1000w hps to flower our chemdog/sour diesel kush - about 75days of 12/12

this go-around i'm trying '2' 315cmh in a 4x3.5' tent - we are at 65 days and tricomes r 60pct clear , so have a bit longer to go...

do cmh usually take a bit longer... or shorter - does anyone have any experience???
 

oti$

Active member
In my experience cmh have shortened flowering time by a week or ten days in a few grows and not at all in a few grows. I've never had them increase flower time. I've been flowering with cmh for a couple years now. In most cases I've had cmh and hps in the same room and more often than not the plants under the cmh lights finished a week faster than the same cross under hps in the same room. I got these results under 315 cmh lights. I recently started using 630 cmh lights and, for whatever reason, the flower times have been the sames as hps and the plants have been more leafy than I'm used to. Just my observation from limited experience with the cmh tech. I've heard if ither growers getting faster flowering times with cmh, so it's kind of odd to see you report the opposite. You are still a couple weeks out from your typical harvest window, so maybe you'll end up finishing about the same time...
 

zachrockbadenof

Well-known member
Veteran
oti$ - thanks...i checked the plants with my scope today- still have a bit to go- what i did notice handling the plants is that while they are sticky, they are no where nearly as sticky as under hps... now does this mean anything... that remains to be seen once smoked, but at this stage under hps, my finger would be sticking together, and while my fingers are covered with tricomes, my fingers are not all that sticky...
 

Lost in a SOG

GrassSnakeGenetics
There is quite a bit of difference between HPS and CMH

With CMH there is usually more lights and they have a very different light distribution to HPS, slightly more uneven in horizontal position, it's way more blue which effects stomata differently affecting transpiration or stomatal conductance, it's way less heat out put in IR and far IR which amongst other things effects stem thickness and also bud weight. and resin goes through slight cycles of tackyness to slickness.
 

zachrockbadenof

Well-known member
Veteran
There is quite a bit of difference between HPS and CMH
resin goes through slight cycles of tackyness to slickness.

well then i'm at the tackyness stage.. i'm figuring another 10/14days for the kush's (have a josh d tooo), and i also have '1' Zamaldelica from ace seeds- that lady doesnt have a brown hair, still throwing out white hairs- she is prob at least a month or more b4 she is ready, hopefully not much more then that- i grew some ace golden tiger - picked at various times, the last was at 150days... and she could have gone even longer...
 

Lost in a SOG

GrassSnakeGenetics
Ha yeah I remember growing Zamalidelica.. lmao think I flowered it for over 4 months and it still could have gone another 2, actually a lovely if weird smoke.. I don't think i've got the cohones to sprout my golden tigers lol looking at the size they grow to.

Josh Ds look fire from what i've seen, makes sense with it's background..

as I said watch that extra blue spectrum in the CMH, I can only imagine that would make sativas go even longer but I could be wrong..
 

Latest posts

Latest posts

Top