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Sunmaster 600w Cool MH heat vs height.



I'm currently nearing the end of my first week veg on 8 plants in coco (please see my profile for idea of strains, grow tent setup, nutrients etc) and have a question that I'm having a hard time finding a definitive answer to, perhaps because there isn't one?


I've got my plants  (that have just been transferred in the rockwool they germinated in to a coco and perlite mix) under a 600w cool MH from Sunmaster. I'm running a 600w digital ballast, but I understand that dimming is not advisable. However, heat is currently an issue for me (Currently at around 25c-27c lights on temps, but it's been as high as about 31c-32c) I tried changing my lights on cycle overnight to see if it would improve things, and honestly, the additional disruption it causes wasn't worth the 0.5c reduction I got in temps. 


In order to get the current ambient temp I have (25c), it's been necessary for me to raise the reflector about as high as it will go. I suppose my question is, am I doing my young plants a disservice by doing this? Am I better off dropping to say a 400-450w MH, losing a bit of heat with that and lowering the reflector to get back to circa 25c temps, or am I ok doing what I'm doing?


I just got one of those little Highpro fans for the intake, so any advice as to how I should set that up most effectively would be really appreciated, as I currently just have it held in with the drawstrings of my intake opening.


I hope this all makes sense. I've been enjoying reading the forums a lot, some very knowledgable people here! Some absolute world class blaggers as well, which is enjoyable in its own way.


Anyway, thanks for your time and hope to hear from someone soon.

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if you can,- upgrade your extraction, and run it off a fan controller.

this wil allow you to get them under the 600mh

what size is your tent and what size is your extraction? I suspect its too small for the space. 

if you cant upgrade the extraction, lower the wattage to 400, see how that goes, but you will be stuck at that for the grow if you don't do anything about the extract fan


edit to add; just read your profile- 5 inch fan is too small for a 1.2 tent running 600 watts ime. 

Edited by badbillybob

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Hi badbillybob,


Thanks for your reply. Going to go for the extractor upgrade I think. I can just about control everything now, but as the weather gets warmer it's going to be a drag. It's a shame my existing one is too small, as it came packaged with the tent, however the lamp it came with was a Lumii DS, and I guess they give off slightly less heat? Who knows. Thanks again.


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its probably the grow shop selling "kits" that aren't fit for purpose to be honest, they have been doing it for years. that's why most people on here recommend buying stuff separately, to be honest. we have all been there. .

I would get a 6 inch set up with a carboair or mountain air filter in there mate, till then, whack it on 400w

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