What light should I get for a 40x40x78 grow tent from htg? I hear 400w, would this be too hot? and to keep it cool ow would I do this? since theres 5 vents at the top and 2 at the bottom And would it be bestter to use LED's?
Ideas? I have about 500$ for the light and ballast so plz give me ideas and how to keep it cool what fans for a 6" intake, I am growing in the tent and theres 5 6" vent's, what intake fan should I use and what is the quietist? http://www.htgsupply.com/viewproduct.asp?productID=52583 or http://www.htgsupply.com/viewproduct.asp?productID=52583
get the 600 digital with air cooled hood i like the easy cool 6 inch ull need a decent exhaust fan to keep it cool ull get 50% more yield from a 600 compared with a 400 so do it right i personally would upgrade the light 30$
i have their 48x48 size tent with a 400w light in there... I don't do any more cooling than a fan that is able to blow out cooler air... I added a 250w light on top of the 400w (650w now) and im still not having to cool it... Quite remarkable what those little air purifier cooling fans can do for 70 bucks...
Experienced growers benchmark their yields in grams per watt. A 600 consumes 50% more watts than a 400 so theoretically a 600 should yield 50% more than a 400. But grams per watt is misleading since watts are a unit of electrical consumption, not light output. Grams per lumen would be a more useful benchmark. In that case a 600 puts out almost twice as much as a 400 (90000 lumens vs 55000) so, yeah, I would expect a grow under a 600 to, at least, yield 50% more than a 400 - all other grow variables being equal.
[quote name='johnk']Experienced growers benchmark their yields in grams per watt. A 600 consumes 50% more watts than a 400 so theoretically a 600 should yield 50% more than a 400. But grams per watt is misleading since watts are a unit of electrical consumption, not light output. Grams per lumen would be a more useful benchmark. In that case a 600 puts out almost twice as much as a 400 (90000 lumens vs 55000) so, yeah, I would expect a grow under a 600 to, at least, yield 50% more than a 400 - all other grow variables being equal.[/QUOTE Annybody have a source as proof of this, because it just seems like theoretical opinion. Promising the OP (obviously a very novice grower) that by Simply adding an extra 200w of light they they are guaranteed an 50% higher yield, If this were the case I think we would see grow cabs that were just covered by a variety of lights until there was no space remaining for more bulbs, thusly maximizing your yield..... My point is all lights and plants have a usable lumens limit... I would be willing to bet that most soil groweres do not reach the 1 gram per watt goal. especially a novice........... So has anybody grown the exact same thing side by side, one under a 400 one under a 600 and consistently (regularly, more than a couple times) achieved a a 50% greater yield out of the 600?????
No one is saying that the OP will achieve 1 gram per watt in yield or that "simply adding an extra 200w of light they they are guaranteed an 50% higher yield . It is not simple to add 200w of light - and there are NO guarantees. But grams per watt is the benchmark to judge yield success/efficiency. The OP may only achieve .5 or .25 grams per watt but the point is that grams per watt, or more accurately grams per lumen of light is the unit of measurement commonly used to benchmark a grow. You'll note that I added the caveat "all other grow variables being equal". I contend that in two identical grows with identical grow spaces, numbers of plants, temps, humidity, strains, grow techniques, nute schedules, etc. - one under a 600 and one under a 400 - that the yield under the 600 should be at least 50% more. Yes, there is a diminishing return in supplying more lumens than the plant can use - the limit is commonly held to be about 10000 lumens per square foot. If we were to take, for example, an 10 sq. ft. grow space under a 55000 lumen 400w hps, that works out to 5500 lumens per sq. ft. A 600 would output 9000 lumens per sq. ft. Why wouldn't you think that the 600 would yield at least 50% more with almost twice as many lumens per sq. ft.? Do you think the yields would be the same? If yield was not directly correlated to the amount of light then why aren't we all growing under a couple cfl's?
100% Agree. Throwing more light into the a grow where other factors are not, at least, normalized (if not optimized) will not increase yield - more likely decrease it.
What fan should i use etc?.. and I think ill stick with 400w cuz 600w dosent seem possible to add 50% more yield cuz of grow space, and for the reflector I will go with the 6" cool tube
OK I'll stick my neck out. I would lean towards a 600 watt also. If your yeild was increased my a little it would probably still justify the extra cost. And if you completly suck at growing, the 600 is more marketable (IMOP) If you are not comfortable with your grow skills you might want to go with T-5 easier to keep cool and get your experience with less dynamics and once again it's easy to sell to more advanced growers for veg. I would agree 50% yeild increase isn't going to happen at this level. I always consider return on investment and exit stradegy. I have to admit I never dreamed of owning a 400 watt light. But maybe because the smallest space I build in 6.5x6.5x6.5 and I use a single 1000 watt . Vetical grow.... Now I must a admit one of the down sides of 600 is bulb choices. HPS or conversion bulb for veg. Well don't chop my neck off. Just something more to think about. Remember there really isn't a wrong answer. It also depends on growing style.
I was thinking the t5's but i hear not as good as hps and if i was that worryd about heat that much id use led's
Out of respect for the board I'll PM you link to anouther forum with buds grown from T-5's. There has been a couple comparisons done. Do a couple searches.
Here's his DWC/BB thread. Check out his other stuff - do an advanced search for "Rumpleforeskin" posts. You'll get several thousand, but check out his DIY stuff - fuckin' wizard. And I should know...... http://forum.grasscity.com/do-yourself/121335-lets-build-bubble-bucket-step-step.html