What kind of temperature should I be shooting for in my growroom? I would be interested in knowing the higher and lower range I should shoot for and the general effect temperature has upon growth and overall yield? My room currently hovers in the mid to high 80's. Any input would be appreciated. Thanks again folks!

Optimal is 78. Over 90 is killing them. Upper 70's low 80's is good. Dont go above 90.

i've always heard 75 for the best growth when everthing is dailed in just right

76-78deg F. is perfect in a non-CO2 enriched atmosphere. If you are using supplemental CO2 of some kind (ppm above 1500 or so) plants can thrive in temps up to 93 or so. I run my room at about 91F. with my CO2 running about 1900ppm. getting great results.

above 75 farenheit the cannabis plants stomata begin to close, the enrichment is only compensating for the overheating. light beyond 5500 foot candles of photosynthetically active radiation bounces off the plant as heat[/quote]

At higher temps. plants transpire quicker. Even if the added CO2 is only compensating, the plant is still uptaking nutrients faster. I've done comparisons and the hot, CO2 rich room always out-performs the cooler room; except that the cooler room produces frostier buds.

76-78deg F. is perfect in a non-CO2 enriched atmosphere. If you are using supplemental CO2 of some kind (ppm above 1500 or so) plants can thrive in temps up to 93 or so. I run my room at about 91F. with my CO2 running about 1900ppm. getting great results.

That's fine for the strains of plants you're growing and other strains also, but there are strains that WILL NOT grow at temps over 88 F

Your buds look great Ryan!

above 75 farenheit the cannabis plants stomata begin to close, the enrichment is only compensating for the overheating. light beyond 5500 foot candles of photosynthetically active radiation bounces off the plant as heat

You guys are both right IMHO:

I've seen test grows in sealed rooms completely halt growth at 90 degrees with CO2 enrichment. They were commercial tests done by medical licensed growers hired by a nutrient company. The plants constricted, shrunk and died. They looked like a 120 year old person.

The test was done with different strains in different rooms.

The best advice for anyone growing in a non CO2 room is 74 to 78 F
In a room with CO2 you should not go over 85F unless you are prepared to carefully check and monitor the plants. Once a plant starts to die from CO2/heat poisoning it's hard and wasteful to try to get a good crop from them.

The best thing to do is grow several crops out at different temps and see what THAT strain likes the best. Just like nutrient levels, strains like different levels and temps which goes back to their blood line and where they originally come from.

that the cooler room produces frostier buds.

Give more sugar (carbs) to your hot room plants than you would to a lower temp grown plant; and still give them the sugar during your water only flush stage. They'll still put on sugar weight all the way to the chop

Liquid Light from Dutch Master helps your plants use 60% more of that reflected light energy. I figured that claim was mostly bullshit, till I tried it.

Not everyone has or uses certain suppliments.. including CO2---
SO temps should be based on the "baseline" and adjusted IF you do use the "supplimental aids"....
Most plants prefer temps that are between 68-72f with the lights off and 70-80 lights on. too mich of a variation can cause ph fluctuations, changes in leaf color, or stress the plants--- especially if way over or under "baseline".

Lower temps in veg and higher in bloom- followed by slightly lower toward harvest mimics seasonal changes, and we have found it to lower the incidence of late-bloom hermies- and we get a high ratio of females when vegged a bit cooler..... This is also written about in many books on growing as well as Manuals for Greenhouse growers... (no not Pot... but still pertains) That undesirable Genetic vartiables tend to be triggered by extremes in temperatures, or a large variation in the temperature the plant would encounter in it's "natural" environment" as opposed to indoors under lights or in a greenhouse.

Not everyone has or uses certain suppliments.. including CO2---
SO temps should be based on the "baseline" and adjusted IF you do use the "supplimental aids"....
Most plants prefer temps that are between 68-72f with the lights off and 70-80 lights on. too mich of a variation can cause ph fluctuations, changes in leaf color, or stress the plants--- especially if way over or under "baseline".

Lower temps in veg and higher in bloom- followed by slightly lower toward harvest mimics seasonal changes, and we have found it to lower the incidence of late-bloom hermies- and we get a high ratio of females when vegged a bit cooler..... This is also written about in many books on growing as well as Manuals for Greenhouse growers... (no not Pot... but still pertains) That undesirable Genetic vartiables tend to be triggered by extremes in temperatures, or a large variation in the temperature the plant would encounter in it's "natural" environment" as opposed to indoors under lights or in a greenhouse.