It’s been a long time since I posted and even longer since I was active.
I’ve been studying the relationships of the effects on root zone temperature to dry weight and have come to a few conclusions.
For those who are interested (please forgive me if I’m covering an old topic) I’ve been looking specifically at the sweet spot of root temperature to increase overall weight.
So most of you hydro growers will know that low water temperature will cause slow growth, affect plants resilience to disease and pests and lower yeilds.
The same can be said about root temperatures/nutrient solutions that are too high.
On average 12c or lower and 25c or higher will cause significant problems in general.
But a 13 degree difference is a massive parameter to work with. Luckily there’s more specific plant research out there that zeroes in that difference to being ideal temperatures of your roots/medium is between 17-23c with as little fluctuation as possible in a 24 hour period. Think of how rapidly your grow room cools down when the lights turn off… This can cause significant stress to your plant and lower yeilds.
If we go up the scale something interesting happens, at 23-27c your roots will actually go into overdrive and you’ll see pretty explosive growth. Sadly this doesn’t equate to higher yields. In fact you’ll have more airy buds, more stalk and very lanky plants. This is obviously an issue when your plants are going into their stretch period when flipping to flower.
To combat this we might want to slowly reduce the light cycle to even out the rapid temperature drop, or we could also think about having some small tube heaters on a thermostat that come on when your lights go out (or we can do both in different combinations.) This is of course assuming you don’t have water heaters/chillers in your res that your setting.
As a coco grower I don’t have this luxury but even when I’ve grown using traditional hydro methods I’ve only bothered with heaters and chillers when running much bigger grows. The best results (this surprised me) I’ve had haven’t been with a soil/water probe connected to tube heaters and set to a particular temperature but using an external thermostat built into the heaters
So (and most importantly!) The sweet spot for optimum nutrient uptake temperature range I’ve found is between 28/32c (at the top of the plants) with lights on and a drop to 18/19c (controlled by tube heaters around 2" off the ground) when the lights go off.
There’s a ton more science involved here and I’m more than happy to go into depth or answer anything I’ve missed.
Again, please accept my apologies if this teaching you lovely people to suck eggs and I hope this makes sense and is useful
That is a pretty big range. I don’t run hydro but depending on time of year I can go as low as 14C and as high as 30C
I never understood the “go suck an egg” derision. Is sucking eggs a bad thing? I mean, I eat them. Is that a form of suction? These are questions I don’t want to have to answer
Yeah it’s a weird saying and doesn’t really make sense. TBH it’s not something I’d ever say in RL either. Dunno why I used it here, for want of a better phrase I think.
Now all I’m imagining is what it would be like sucking an egg and then the realisation that I stuck myself right in the firing line for a bit of banter
Yeah, I think they’re the bottom and top end of the scale.
If my heat difference is that low though and it’s dialed in just right with a strain I’ve run a good few times, I can generally hit 1.2gpw without too much hassle.
For me it’s the final price in puzzle but seems to be like something most people don’t bother with?
That’s some good weight dude.
Sorry, my English isn’t the best! Weekday I meant to say is that nomatter the strain it’s possible to get 1.2gpw. that is my mean average weight.
What interests me is the temperature fluctuations, can you give me some more information please?
There’s so much to consider when talking about dry weight yeilds. I think one of the biggest things is the moisture content of the dried flowers. A 2 day extra cure can reduce weight by a third, then we’re taking about a huge difference.
I’ve only recently started using different lights and experimenting with this. I’ve currently got the Telos 10 pro LED running alongside a Phillips 600 green power HPS all within a 1.2m tent.
These days I simply don’t have the space to run real experiments with a control. So I just focus on one element when everything else is dialed in nicely.
One thing I can guarantee though is that if you can get your root temperatures on point your yeild will increase!
That’s a shame. The tube heaters are really cheap to buy and cheap to run. This would cut your winter fluctuations down.
I grow in the corner of a garage and in the summer the sun beats down on the thin metal door and it gets to hot to touch, in the winter is the opposite. I installed some 180mm kingspan and it’s a good compromise.
What lights in what size tent are you running and what strain?
