temp questions...

I just watched this video here: http://www.youtube.com/watch?v=xJIjJ5nZUZw. The grower asserts that the ideal room temperature for growing with LEDs is 85%. His argument is that with traditional lighting although the room is 75 degrees (ideally) the canopy is 85%. With LEDs the canopy and room are the same temp. Thoughts? Also - I run a DWC system where I try and maintain my water temps between 65 and 70 degrees. With increased room temps will this affect my water temps? Is a 20 degree difference between room and roots going to produce adverse results?

Anyone? I've always tried to keep my room around 75.

Leaf temperature is what really matters. So what ever you need ambient to be at to achieve optimal leaf temp(not sure myself what that temp is). But that is the theory.

74*-78* always does great for me. But I'm a soil guy. With CO2 temps can be higher. In a operation like the pro source one, they probably use co2.

Then one of the most important thing to a hydro setup is a chiller. Also the priciest too. But that would negate any slight rise in ambient. If you talk to AT, ask robert your question.

I keep my daytime temp 70-74'F and at night I let it drop to mid 60s and my girls couldn't be happier. It all depends on the strain, humidity, your CO2 levels and countless other factors. No one thing by itself is definitive here. It is more about finding out what your plants like and being consistent about it throughout the grow.

as long as you can keep the water . cool. water chiller. very costly to run 500 watts. per chiller for small grow . larger grow . then about 12 plants per 800 watts wasted to cool water . running 24 hours a day. I hate hydro. you can push the temps to 85f flowering with out co2. veg about 90 with out co2. very hard to keep that water cool. I but my cloner set to 60 f works best for me. in soil same situation with temps with out co2. but with high out put of co2 veg and up to 6 weeks of flower. and strong lights. the plants love higher temps 85 to 95 f . very hard to do hydro higher temps because have to keep water cool. any temp over 75 change the water every day very costly. or chance root rot green fungi . serious hydro hater here. rather use soil and add more lights then waste the electric on a water chiller.

Btw, about the chiller - everyone told me the same thing when I was setting up my Aeroflo2 60 (my first hydroponic grow) so I invested $500 in a nice chiller with a decent pump and stainless coil. I have not turned it on at all in weeks, my res temp is at a steady 68'F. Of course I do live in the high desert, I haven't even heard the AC click on since September. The ground stays cold and I'm guessing it keeps the res cold as well. It will probably change come summer when it's 120'F outside... So not that I regret buying the chiller - just that, once again, a lot of conditions to consider.

A plant, in my opinion, doesn't really give a fuck how the temp was produced whether it be LED or any other light source. CO2 will enable the plant to accept higher temps, but otherwise 90 degrees is 90 degrees. Root temp is what you need to worry about with hydro, as that shouldn't be higher than 70.

I have noticed that some varieties can handle high canopy temps better than others. If the temps get too high (>85f) the first annoying thing is that they take longer to finish or seem to never finish. You might see new growth with foxtailing, a lot less frosting than you are used to and generally fluffy buds. They may also seem to have less aroma/flavor.

Personally I would rather have too low temps than too high temps. In my opinion 75-80f canopy temp is the sweet spot for most varieties and that applies for HPS and LED..

Yeah - since I'm going for energy efficiency and LEDs I don't want to start heating the room so 75-85 will probably occur "naturally". I'll keep the RDWC res out of the room which should help keep water temps close without much chilling. I am running CO2 so if the air temps I'll have some wiggle room.

Yeah, I completely agree with using the environment to save money. I find it wasteful when people run AC in the grow room all day long to counter the heat from the lights while running heater in the house because they are cold.. It's cold and dry where I'm at right now so I just pump the air from the outside while running a small heater at night. That takes care of my temp, ventilation and humidity all at once. With that and LEDs my energy costs at my 'normal' rate. The only downside I'm still looking to optimize is CO2, since the way I got it set up now it vents out too quickly. Oh well - every grow is a new learning experience.

I agree, better to work with nature than fight against it. I do the same thing, pump cold air into the flowering room in the winter, dump the heat from the flowering room into the veg room. The grow actually humidifies in winter and the electricity spend on light actually heats the house a bit.

I have been using this bath fan to move the air and it does a decent job. Very quiet 2.5 sones $32 and only uses 40 watts .9 power factor