Dealing with heat issues in the desert...

[Rusty Trichome]

4 200w CFL bulbs in one hood? Wow. Might need to use the vaccuum to suck-out that kind of heat, lol. Do you have to run all 4 at the same time, or can you unscrew one or two till plants harden-up to the heat? (a week or two)

Seedlings don't need light till they break the surface. But yes, 91 is likely too warm. Would move 'em asap, or turn-off the lights. (but turn 'em back on when they sprout) 80ish is max I recommend for germinating seeds.
Have you tried different combinations of lights? Finding out what you can do to lower temps when ambient room temps rise, is a good thing. You can remove one light, or angle the bulb so they are closer together when lit, or further apart, or another fan when necessary. Try different things to see what is the best you can do when it gets hot.

Every growbox, growcab, grow shed and grow room are different. Different shape, volume, different contents. There is somewhat an optimum set-up for each. You have to fiddle around till you find the best 'cooling' technique for you, and use it when necessary. Tiz a good idea to check the temps in different locations of the growtent, too. Dead spots (trapped, stagnant air)heat up quickly.

[darrenlayo]

Thanks. have unscrewed 2 of the bulbs and raised the hood a little. has bought the temp down to 28c/82f. have 10 seedlings all in 11 liter pots and it looks like there is still sufficient light. have 1 sprouter now so hopefully most of them will pull through.

[McToker]

Rusty ~ Thanks for the great thread. I guess I was just beating myself up trying to reach that "ideal" temp. We're in the same climate as you but working indoors in a Homebox. We finally gave in an turned off some of the fans scattered around the area, outside the box, and just cranked the A/C down a bit.

I like your idea about the sheet of plexiglass.

Thanks,

McT

:thumbsup:

[xRedDUBdeRx]

Good post. Im west coast indoor grower here and nothing but desert! Will be helpful next spring/summer =P

TY.

[brainfood33]

This is the most perfectly timed thread I've found so far, thank you so much for this info.

I'm not in the Desert, quite the opposite in fact as I am in the Northern UK and we rarely even see the sun! lol
But I do have heat issues whenever I switch on my second 600W HPS in the flower room as the temps climb from the low 80s with 1 light, to the high 90s when both are on.
This has lead me to limit myself by only using half of the room which really isn't enough for what I need.

I have a powerful exhaust fan with a carbon filter and plenty of circulation but I've been scratching my head to figure out what I can do to reduce the temp with both lights.

I was contemplating putting in an intake fan but there are too many difficulties involved with bringing the air in by stealth and this was worrying me.
But you seem to not rate the value with them anyway?

My main question here though, is that I usually grow hydroponically and will be doing so when using both lights in the future.
Why would it be any different for hydro than for soil as you stated in your opening sentence?
Is it to do with the root systems not having the protection of the soil or do the plants in general behave differently between the 2, maybe more sturdy when in soil?

Cheers!

[Rusty Trichome]

True, I'm no proponent of using an intake fan, but I do realize there are times that one may be necessary. If you have good exhaust, a simple intake hole, (or two) the same size as the exhaust hole is sufficient.

I have not had any experience in going hydro, and thusly don't want to represent that these 'techniques' will work that way. I try never to comment on techniques I've never personally tried before.
The main thing I'd worry about, tho...is how to keep the reservoir cooled enough not to harm the roots.

Have you thought of using a light mover?

[brainfood33]

Despite preferring not to comment on Hydro, I think you might have answered the question.
It will be an issue indeed that the reservoir temps will be too high, and therefore very warm water will be feeding the plants continuosly which is not a good thing at all.

A light mover would be the ideal solution but I'll have to save up for one as I am totally broke at the moment sadly. Can't even buy any green!

I guess another option would be to master the soil grow and ditch the hydro altogether, now that I know that hot temps aren't so scary afterall.

Hmmm, no reservoir, no buckets, no ridiculous amounts of water, no pumps, no rockwool... its sounding good already!

Cheers again Rusty.

[Rusty Trichome]

No problem.

Altho I've never grown hydro, I have had friends that were mighty proud of their accomplishments using it. I was always under-impressed. They looked great while growing, and I guess it got you high ok, but were lacking in flavor.
I much prefer my soil grow. To me, it's easier and cheaper, no risk of clogs or fittings coming loose. Others proclaim it's advantages, but it's just not for me.

[Obscurus]

This is a very great thread. It gets over 100 out here in NM during the summer sometimes, and I was definitely concerned about the temperature a lot more than I should have been I guess. I was also keeping the Hygrometer near the canopy of the plants.. I am going to move it and see what the ambient temp is like.

Thanks for spreading the info!

[mojavemama]

I'm a desert grower, but decided to experiment with an indoor-outdoor grow.
It's labor intensive, but I've found ways to compensate for the lack of humidity and intense sun and heat.

My girls are all in 3 gallon pots, 5 of which fit into a rolling garden cart. I fill the bottom of the cart with river rock, then add an inch of water to help with humidity.

Then I wrap each pot in layers of wet newspaper, and lay strips of wet newspaper on the top of each pot's soil. Only the leaves are now showing. I then cover the sides of the cart with shadecloth, so the cart itself won't get so hot.

The plants have been out every day, in temps reaching 104 degrees, and have done fine, showing no stress. The soil is always cool when I check it.

About 3 pm, it really gets super hot, so i move the plants into the shade until sundown, when I take them all inside, and put them in my grow room. In the grow room, I have a humidifier that keeps the room at about 60% humidity, and it's also air conditioned, and has a good sized overhead fan.
I'm now into 12/12 flowering, and still letting the plants stay outside during the day. They are very healthy and happy, in spite of the intense sun and desert heat.

But like others have already said, never let the soil get too hot or dry. Overwatering is not normally a problem here in the desert. My plants drink about a gallon a day each.

Here's a picture of some of my plants in the desert sun. You can see they are green and healthy, in spite of the direct sun on them most of the day.