Does my greenhouse temp is too hot? its around 90F. with proper in and out air vent.

Yeah, 90F is too hot.
You wanna try and keep it around 79-83F

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"If you give a man a bud, you'll get him high for a day... if you teach a man to grow, you'll get him high for a lifetime."

Should be fine ...that's where mine hangs about too ....Just think of how hot it is in Mexico in the middle of summer the plants down there do just fine.... though if you could drop the temp just a bit probably wouldn't hurt If it a hassle leave it =) If it goes over 90 and your plants don't like it they'll let ya know pretty fast...

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I would try to lower it. The only reason to have temps like that is if your using CO2.

But if you really dont want to than fuck it but your plants will grow much better under better temps.

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Its grow time

Maybe think about blinds in your green house or some shade device.. this will drop the temp.. if this fails get a big exaust fan vb

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oryt, i think i need to lower it down then. does hot temps cause dying of leaves?

You can get a greenhouse themostat...it's a thermostat that intagrates into a window valve that pushes open the window and closes it automatically when the temps fluctuate. A very common tool widely used in all greenhouse applications.

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Smells Like Hay.....It's OK

they have some nice exaust fans at Home Depot

I manage to lower it down to 85F hope it works.

Yea your fine. The outside temps will just lower from here out anyway.

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Its grow time