I have that same exact tent with a 400 watt and air cooled hood. It is in an air conditioned room and during the hot summer months it's hard enough to control the heat with a 400. In fact, if I would have had anything more than a 400 last summer I probably would have ruined my grow.
It's simple. That tent isn't made for a 600. Even the manufacturer says so. Get the dr120 if you want a 600. I know a 600 will be too hot for that tent. It will get over 100 on you no problem since my tent can get over 90 and that's in a room with ac.. Flowering in 100 degree temps isn't going to be fun.
Also, I read some folks suggesting dimmable ballasts. Now from what I've been told and this may not be true, dimmable ballasts require a different bulb when you dim down. If so that sounds like a pain. I was also told that if you dim down a 600 you have to dim it to 50% and then put a 400 watt in it. Because you're using 300 watts with a 400 watt bulb it's not giving you the full potential of the bulb. This sounds like it makes sense but I'm not sure about this.
If so it sounds like dimmable ballasts are not any good.
On a side note you can get great results with that tent and a 400. Plan on 3, maybe 4 plants at one time with 3 of the plants being big and the fourth small. Never done sog.
Things get tight in the 90. Branches get tangled near the end but it's all good. The dr90 rocks for it's size. I didn't have an inch more space so the 120 wasn't an option.
Final thoughts. You can get away with a 600 some of the time but there will be many instances where it will be too much heat for that small of a space. I think you will turn what would be normal temp days into days where you're running hot and you will a battle harmful heat much more often with a 600 in a 3x3.
That's very interesting....I considered that my inline fan may be a bit weak for this tent running a 600w and at this point, I'm more willing to upgrade my fan than I am willing to downgrade to a 400
My average ambient temp in the room that will house the tent is like 73-75 in the winter and my ducting will have a very short length and minimal bends. Eventually there will be a carbon filter when the bitches start stinking so you sold me on the idea of upgrading my fan. I do however think that I can get away with my 197CFM fan w/o the carbon filter attached, but I'm on board with ya on the idea that this fan will not sufficiently cool a 600. Thanks for the feedback!
I'm going to second Edgar9 on that one. Get the 400 and if it turns out that in your case heat from the 400 is easy manageable than you can always flog it on ebay and get the 600. But if you get the 600 and you can't manage the heat than you have poor harvest or no harvest at all. Better safe than sorry imho. I grow in a 2.5x3x6 with 400w hps, only once a year in winter when i can pull cold air from outside to keep the temps down and i JUST about can manage decent temps. I dont use the cooled hood though.
Air cooled glass sealed hood is the key my friend. I used 2x150w hps on my last ghetto style grow and those babies kicked out some heat but I had a piss poor ventilation system setup. If I have to hookup a 2nd inline fan to pump air into the tent as well as out of, I will do so =]
i run a 600 in a 4x4 tent with a 440cfm fan cooling the light and a 190cfm fan/carbon filter exhausting the tent i just barely stay below 80 in a room that is 68 degrees.
kane
Is that a glass sealed hood? I feel that a sealed hood is key....gotta contain that heat for efficient evacuation otherwise it will easily contaminate the temps in the tent.
I like the way you think. Much appreciated.
I have the same setup but no 440cfm fan. Just a 190cfm on a carbon filter and its cooling the light. Rooms 72-73, tent at canopy is 72-79 with 73-75 being the average. Id try and get your cool air source closer to your intake.
To the op: id go with 600 maybe get a digital dimmable ballast so you can run it at a lower wattage in case temp gets too high. My ballast does 660w, 600w, 450w, and 300w.
The digital ballast with a dim adjust doesn't sound like a bad idea in the event I have heat issues. Something to consider there....I'm actually kind of leaning towards a sun systems digital b/c the warranty is 3 yr free replacement & 2 year pro-rated for a total of 5 yr warranty.
I run 600watts LED in my 3x3 tent and it's great, very great 400W hps won't get you hard dense nugs
LED's eh? Got any pics from that grow? I'm not sold on led's but I'd love to see your results to prove me wrong though!
If you have the right genetics and a guy who knows what he's doing with the right nutes you can get nice hard, dense nugs with a 400 IMO.
Check out the 400 watt club on this site. I see a lot of guys with awsome buds and plants.
I've been scoping that thread for years now....started @ the 150w club and those guys even pull down some good looking harvests. I just want to make sure the buds have the ability to dense up. Don't want no FLUFF.
The Hydrofarm Phantom 600w is dimmable to 450w and 360w, a very useful feature when confronted with temperature control problems in small spaces. While I was initially unenthused about being limited to the 600w bulbs, I have found that they are more advantageous than their lower wattage counterparts in dimmed mode due to the longer arc tube. That being said, it does take some bulb burn time before they will cease a somewhat noticeable flickering effect. As far as I can tell, the brief period of flickering does not have any negative effect on the plants.
I am currently using (and testing) some of the more expensive bulbs for this ballast. My initial test results show that spectrum worries are marketing BS and that the cheapest industrial bulbs are as good as any. But the testing is not complete, so we shall see how the final results weigh in.
Good post there man. I always wondered if those expensive bulbs were worth the money or just advanced nutrients type of marketing hype.