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Room temp problems


New Member
alright ya'll need ta pick yer brains....

my first grow I ran one 1000w hps and with ventilation room ran 80-85 degrees. (perfect)

this time I am running two 1000w (mh for veg) and it ran temps up to 95... I upgraded air flow in-out and added 2 fans just too move air around.

still running 95 so I added a 5000btu A/C ... it's running constantly and I'm only getting down to 90

I do not have the vented hoods for the lights I know that would cure the issue But can't afford e'm at this point

ANY creative ideas?


Active Member
You could use a different light source for you veg, although MH provides a better spectrum and light temperature, fluorescents or CFLs can get the work done just as good and at a fraction of the cost, this will also lower your temperatures. MHs create a lot of heat.
CFLs and fluorescent tubes are more than enough for vegging, you don't need 2000w MH for that.


Well-Known Member
5K BTU is about the smallest a/c you can find. I have one as a window unit and it made about an 8 deg difference. They are close to worthless. For not too much more $$, you should be able to get something closer to 10K BTU.

When I was 1st setting up my flower room, I ended up with cold/hot air fighting against each other. I now have a flow pattern. The cold air comes from 1 general area and the hot is exhausted on the other side. I also use a fan to push air up towards the exhaust.

If you don't have a good flow pattern, it won't work as well.

Upload a pic or drawing or basic description of your air flow setup. Is the exhaust on the other side of the room from the A/C? How are the in/out fans positioned?

Does the 5K A/C have an econo setting and a temp setting?

Can you return the 5K and get an 8 or 10K?

Is your exhaust passive or forced?

I just added a WalMart HV exhaust fan for < $20 and it seemed to make about a 4 deg difference.

Where are you measuring the temp? I hang a temp gauge from the light down to the top of the plants.


New Member
ok brother grower, you can see yourself that clearly and undeniably, vented hoods is the biggest single thing you can do to fix your temps right now.

so, your obviously looking for a free or super cheap fix ;)

somehow you need to seperate the air around your plants from the air around your lights and vent them seperatly.

my first succesful bodge job and definatly a "DONT TRY THIS AT HOME" due to the high risk of fire, i tested only to see its feasability.

i built a massive cooltube out of polythene sheeting big enough that the bulb was never nearer than 9 inches from the 'tube', this is whats considered around the safe distants for plants with a 600hps., i then fed my carbon filtered air into this from the bottom which caused positive pressure inside the tube (and a million celotape patches to stop air leaks) and then vented out of a hole in the top.
the experiment was a complete success, but not one that i could sleep or walk away from while active.

i would next like to try attaching battons to the walls of my grow room and spreading a thick clear cheet over them to form a wall to wall seal, seperating the room into 2 vertical rooms, the top one entirely dedicated to shifting the light heat away.

just my thoughts and experience for you to digest. :)

i didnt seem to upload pics of the final prototype, just some of the steps i took on the way, i will try to find the lost pictures, but i may have lost them forever in my last move =/


New Member
Well ..... I bit the bullet but I think I got a good deal, picked up 2 Saturn 6" cooltubes for $110 each... nice big reflective hood not just the shitty bat wing deals....testing temps tonight... thanks for all the input though guys.....but now my follow up question...lol


New Member
Now on a drip system, 3gal. bags, if watering ones before lights on and once after what would the recommended amount of water be per watering? my system is putting out 1cup in 1min. per baby, is 1 cup good ? not enough ?


New Member
ok my friend, you didnt really give us the right information to answer the second question ;)
what medium you using, are you trying to only drip the exact amount of water or goin drain to waste.

in anything that is considered a soil grow, you only want the soil to be ever so slightly damp, the more oxygen you pump into your water, the wetter you can get away with having your soil as the main overwatering concern is that water in the soil loses its oxygen and the roots suffocate.

unless you find someone with the same drip system/media and pot size, your probably going to have to tweak it yourself to get an exact measurement.

if not oxygenating water, then running a bit dryer than you should is safer than overwatering, but if using h2o2, then being slightly wetter than it should is safer than being too dry.

its a balance between dry spots in the medium and drowning the plant....there is a reasonable bit of wiggle room between the 2. =)


New Member
sorry, I'm in 3 gal pots, using pro earth #2, and I am watering only exact amount, I am aerating my reservoir and after the 3rd week will be running cutting edge micro nutrients.(grow,bloom,another one c/r and sugaree toward the end)

I'm not using drippers just a 1/4 line into pot

just worried 1 cup may not be enough?


On Vacation
try cooling the bulbs w/ the AC opposed to cooling the room, use fans/blowers to route the cold air over the bulbs/hoods, that's one thought, or,,,, make the grow area smaller so u r cooling less space is another thought, also,,,, maybe if u reduce the speed at which you are pulling the cold air out of room. My 2 cents.


New Member
i would give an established plant in well draining soil in a 15 litre pot about 2 litres every 3 days at a guess.

which if my maths are correct is only about 0.5ml per minute.

i myself want to get into drip irrigation, but have not yet used it. perhaps i will during my next crop =)


New Member
heat is resolved idle at 82 .... on the watering I'm imagining watering one hour before and 1 hour after light cycle every day (is this too often? , I've heard some say it's good to let e'm get a lil dry once in a while ????


New Member
as mentioned, ive no current experience in drip feeding.

i have an experiment for you to try if you want.

let a plant go dry, as dry as you dare. then weight it.
whatever the weight, go make up some water that equals say 25% of that weight and water the pot with it. assuming that 25% added water isnt too saturated (making the number as i go along, your looking to make the soil just a little moist).

now you have the weight of a plant pot with the right amount of water in it.

you can now set your water rate by the weight of that pot, if it gains weight the water is running too fast, if it loses weight its too slow.

just a thought =)
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