Kill switch for HPS to prevent overheating with supplemental lighting

I have a 4x4 grow tent with a 6 inch air cooled hood with 400 watt HPS. Supplemental lighting is 9 band 150 watt LED and two 300 watt cfl. If I do not wake up early enough or am away for the morning the HPS still brings the temps near 90 and remains there for a few hours. I have a 120 CFM exhaust fan and a 6 inch inline intake fan bringing room temp (about 72 degrees).

My question is if i install a kill switch on the HPS to turn off at 86 degrees and then on at 78, the HPS should turn on for the first hour then off until the tent cools down naturally or is opened by me, would this cause significant stress on the plants or equipment? Are the LED and CFLs enough to continue the growth cycle for the few hours the HPS is down and not ruin the flower cycle?

With all that light in there I can't imagine giving the hps a rest from time to time would throw off the flowering cycle. I could be mistaken however. I would try to bring the temps down if possible. What is the temperature without one or both of the cfls?

As far as it damaging the hps, it is recommended a bulb be allowed to fully heat up before shutting it off and allowed to fully cool for about half an hour before restarting.

cool with the CFL and LED the temp is a few degrees warmer than room temp, about 75. It takes about an hour or so before the nighttime temp low 60's reach the danger zone in the mid 80's with the tent door sealed.

A temperature control switch is $3.50 and anything else would be super expensive, that i can think of. Other cooling suggestions are welcomed!

I think you just better up the extraction. That light is precious, it's really not a great idea to turn it off to reduce heat. I've got a 600 hps (running at 660) in a 120x120 roofqube, so the same size but probably way shorter cos of the apex top design. Got a cheapy vents tt 125mm running on slow speed and it keeps the temperature down fine. I'm using a parabolic reflector rather than an air cooled hood. I think the general opinion would be I should be running 6' or bigger fan, but 5' seems ok.
If you don't want to invest in a new fan, could you use another length of ducting to reach a cooler source of air for the intake?

you need to exhaust better not shut off the lighting

qwizoking said:

you need to exhaust better not shut off the lighting

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I agree with this quote, but that might not be possible with your setup, I don't know. But turning off the light runs opposite of the perfect scenario for your girls.

Apex Jr, cost $200 (I've promoted this fckn thing like 100X already and I got NO dog in that race) ...
Anyway, it does all kinds of shit, including a hysteresis for MH lights and temperature variables that will shut off your lights above certain tolerances...

but telling weed smokers shit is like teaching aardvarks how to spell aardvark

Something very wrong here if you gotta supplement your HPS with shitty led or low end cfl, remove that crap keep the hps and a better fan on a temp. controller once heat gets above 75f another fan comes on ....easy!

JohnnySocko said:

Apex Jr, cost $200 (I've promoted this fckn thing like 100X already and I got NO dog in that race) ...
Anyway, it does all kinds of shit, including a hysteresis for MH lights and temperature variables that will shut off your lights above certain tolerances...

but telling weed smokers shit is like teaching aardvarks how to spell aardvark

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do you have a link for that?

Cottleology said:

do you have a link for that?

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Here

and BTW, while this is for aquariums, it can control lights (or ANYTHING plugged into it) based on temperature, pH, liquid levels, et et...
basically you can have fans, chillers, lights or pumps all controlled based on environmental criteria
pumps can shut off if your res drops below certain limits, you can cycle watering/fert times by second intervals or come on/off based on whether lights are on or the pH changes, yada yada yada

like I said, $200 worth of insurance is cheap considering what a grow is worth

x10 on Vos!

vostok said:

Something very wrong here if you gotta supplement your HPS with shitty led or low end cfl, remove that crap keep the hps and a better fan on a temp. controller once heat gets above 75f another fan comes on ....easy!

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Shitty LED?...lmfao....whatever.....anyone who has done even the least little bit of research into what a plant needs lightwise will tell you that the 640-665nm red spectrum does wonders for the bud.....whatever...

greenlikemoney said:

Shitty LED?...lmfao....whatever.....anyone who has done even the least little bit of research into what a plant needs lightwise will tell you that the 640-665nm red spectrum does wonders for the bud.....whatever...

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It's probably been about 3 years since I looked into anything LED related. Curious how far they've come in the past few years. I predict that within 10 years they will progress to the point where they will become your standard grow lights. Change happens slow. I can still remember how resistant folks were to electronic ballasts when they started becoming affordable.

JohnnySocko said:

Here

and BTW, while this is for aquariums, it can control lights (or ANYTHING plugged into it) based on temperature, pH, liquid levels, et et...
basically you can have fans, chillers, lights or pumps all controlled based on environmental criteria
pumps can shut off if your res drops below certain limits, you can cycle watering/fert times by second intervals or come on/off based on whether lights are on or the pH changes, yada yada yada

like I said, $200 worth of insurance is cheap considering what a grow is worth

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I've been preaching about aquarium controllers in hydro for a while now. Apex Jr is cool cause it's web enabled right out of the box...Though I think a RKL is easier to program.