growtek
Member
- Joined
- Dec 9, 2008
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Hi all.
This is an area I've been interested in a few years.
There seems to be a root temperature range for optimal growth (73.4 - 80F for tomatoes. Chart from U of Ohio Hydroponic Program, last pic).
I'm not sure what this is for MJ, but it seems around 80f they start exhibiting signs of heat stress.
I bought a water/root thermometer and my DWC consistently runs 2-3 degrees lower than air so once I get above 82 I'm having problems. I can vent the room more often but then I lose CO2.
I built a rinky-dink heat exchange system. It's passive (sits outside the room). When the plants are older and drawing water quickly it can lower the temps (we keep our house at 67). This passive system lowered root temps about seven degrees. I could run higher room temps and my plants never seemed to mind.
Did it increase yield? I dunno, it was a great haul although I never officially measured it. I think the buds from this grow were extreemly tight and resin filled which for me is the main goal.
TEK STUFF: This is a LONG article written in Practical Hydroponics. It compares a variety of hydro systems and root temperatures. Scroll to the bottom for lots of comparison pics of root mass, coloration, growth etc. (no pot, LOL).
http://www.hydroponics.com.au/php/viewtopic.php?t=94
This is an area I've been interested in a few years.
There seems to be a root temperature range for optimal growth (73.4 - 80F for tomatoes. Chart from U of Ohio Hydroponic Program, last pic).
I'm not sure what this is for MJ, but it seems around 80f they start exhibiting signs of heat stress.
I bought a water/root thermometer and my DWC consistently runs 2-3 degrees lower than air so once I get above 82 I'm having problems. I can vent the room more often but then I lose CO2.
I built a rinky-dink heat exchange system. It's passive (sits outside the room). When the plants are older and drawing water quickly it can lower the temps (we keep our house at 67). This passive system lowered root temps about seven degrees. I could run higher room temps and my plants never seemed to mind.
Did it increase yield? I dunno, it was a great haul although I never officially measured it. I think the buds from this grow were extreemly tight and resin filled which for me is the main goal.
TEK STUFF: This is a LONG article written in Practical Hydroponics. It compares a variety of hydro systems and root temperatures. Scroll to the bottom for lots of comparison pics of root mass, coloration, growth etc. (no pot, LOL).
http://www.hydroponics.com.au/php/viewtopic.php?t=94