Are My Lights Too Low?

Last two of mine burnt up.. went into the room to find the buckets empty of water and a plant burnt to a crisp. The temps hit 93-94 throughout the 12 hour lights on period.. don't know what else I can do to lower temps besides an a/c unit, which I cannot afford to run at the moment. I'm trying to keep the water topped daily to prevent water from running out (I didn't think a plant could drink so much, but with the high temps.. possible?). Trying to keep the lights low as possible to prevent stretching (didn't do so well on the one with buds, lol).. think it's too close though considering the temps?

Maybe mention what lights you are using?

what are you running for a light?
your thermometer should be shaded from direct light.
it's black which makes it heat up.

Morriston55 said:

Maybe mention what lights you are using?

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I suppose that may help.. the led is a mars hydro 300w panel, and the other is a 315w CHM fixture.

Aby55 said:

what are you running for a light?
your thermometer should be shaded from direct light.
it's black which makes it heat up.

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How would I get an accurate representation of the temperature at my canopy level, without having the thermometer at about that level exposed to what the plants are?

IMO distance is ok but temps are too high, you will have to water more often due to evaporation and transpiration, try running only 1 light until the weather cools down or some way to increase air exchange to try and get the temp lowered.

JohnCee said:

I suppose that may help.. the led is a mars hydro 300w panel, and the other is a 315w CHM fixture.



How would I get an accurate representation of the temperature at my canopy level, without having the thermometer at about that level exposed to what the plants are?

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your cmh hood isn't a vented hood? it should be. that will cool you down 15-20 degrees f.

lights are too far away for ideal intensity, but you can't get them closer unless you cool it. the mars will probably be ok if you get the cmh hood air-cooled.

JohnCee said:

Last two of mine burnt up.. went into the room to find the buckets empty of water and a plant burnt to a crisp. The temps hit 93-94 throughout the 12 hour lights on period.. don't know what else I can do to lower temps besides an a/c unit, which I cannot afford to run at the moment. I'm trying to keep the water topped daily to prevent water from running out (I didn't think a plant could drink so much, but with the high temps.. possible?). Trying to keep the lights low as possible to prevent stretching (didn't do so well on the one with buds, lol).. think it's too close though considering the temps?

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I run my mars 300 11 too 13 inches in flower, no closer or your coverage sucks.

Add a couple more fans for circulation

I don't think your plants are too close to the bulb under normal temps. But the mid-90's is 10 degrees or so too warm.

To tell if your plants are too close to the bulb use the simple hand test. The back of your hand is roughly as sensitive to heat as our plants. Move your hand back and forth until your hand feels warmish. That's as close as your plants should get to the bulb.

It's not too late to bend your main colas to keep them out of the light. Bend the top 10-12 inches towards the bulb until the cola is parallel to the floor. The top will continue to bud/mature despite being bent.

You can get a 20-inch box fan at WalMart for under $20. I think that would be a good investment for you. Put the fan in the doorway and set it so it blows into the room. That should help push cooler air into the room.

When the temps in my flowering room get warmish I often will do an AM and a PM watering. I use only small pots, 3 gallon. Those finishing with larger pots won't have to water as often. Remember, the smaller the pot the more often you have to water.

Good luck, BigSteve.