Root temp for nute uptake or bacteria inhibition?

[sedate]

Why should the root solution be kept so chilly?

I have a hard time accepting that 68 degrees is the optimum range for nutrient uptake given how much better the plants themselves do up at 80. Nevermind the differences in molecular movement at those temperatures.

Is this temperature for nutrient uptake, or bacteria control?

What about a product like Hygrozyme?

Would front-loading the nute-solution allow you to run warmer?

If bacteria/algae growth was not a consideration, would temperature be as important?

 

[thumpnasty]

control of root rot.

 

[convex]

Air temps that the plant thrives on are not the same as what the root zone needs to thrive.

In nature the root mass is underground and shielded from the sun's heat.
Roots a foot or two under the earth will not be the same as ambient.

 

[mrdizzle]

roots are typically in soil, In the ground, which is much cooler than 68*

there is something called the "danger zone" for bacteria, they trive between 72*-110ish. Food service industry deals with keeping food out of these temps for more than a couple hours.

 

[mrdizzle]

If your trying to get the green light to opt out of a chiller it will be a major mistake

 

[Lost]

This system is about the chiller as much as anything else :)

 

[sedate]

So the 68 degrees is a reflection of the need to keep the environment hostile to root-rot and bateria growth?

Nothing else?

In nature the root mass is underground and shielded from the sun's heat.
Roots a foot or two under the earth will not be the same as ambient.

I find comparing things to nature - "how is it outside" - isn't the best way to examine these issues. Nature is often a matter of the lowest common denominator in an environment. Easy example - you can veg with 24 hour light - but that certainly isn't nature.

If warmer temperatures stimulate bacteria growth, wouldn't it also stimulate nute uptake? Both are largely determined by osmotic factors . . .

If your trying to get the green light to opt out of a chiller it will be a major mistake

?

I asked exactly what I asked. Nothing more.

 

[JACKMAYOFFER]

In DWC a chiller is more important the an AC once your water temps get above 72 bad things start to happen, You sound like your a pretty smart person what would make you think that the water dosent need to be below 70 degrees? JACK

 

[Boylobster]

sedate, you should also know that there is a direct relationship between water temperature and its ability to hold oxygen (or most any gas, for that matter). The solubility of oxygen in water drops as temperatures rise.

http://www.engineeringtoolbox.com/oxygen-solubility-water-d_841.html

Heavy aeration is what keeps the roots from drowning in aquaculture, so temp is important in this regard as well.

As to higher temperatures necessarily increasing the rate of nutrient transfer, I'm not sure your reasoning is sound - no offense meant. :) But just because *some* bacterial populations thrive at a certain temperature range doesn't mean that such a range is optimal for all functions of all organisms. Some bacteria thrive in anaerobic conditions as well, but that doesn't mean turning off your air pumps is beneficial for your roots.

Nutrient absorption isn't just a matter of osmotic pressure, either - pH plays a huge role, for instance. The root cells certainly use active ionic forces to move elements through their walls, and lots of factors will play into their ability to do that.

In short, no, root temps between 68-72F are not just for pathogen control. That's an optimal range for root health for a variety of reasons. *steps away from podium*

 

[mcattak]

Sedate

I have never really had a problem dripping 72 degree water through rockwool..

Doing dwc now and it is a requirement not just for the critters but like boylobster said DO levels decrease the warmer the water gets...

 

[Kpezzy]

Go outside and dig a hole in the ground 1 foot 6 inches deep, now stick your hand down there, it is very cool underground even on the hottest days, I operate heavy equipment and we would eat lunch down in the trenches because it was cooler down there

 

[sedate]

sedate, you should also know that there is a direct relationship between water temperature and its ability to hold oxygen (or most any gas, for that matter). The solubility of oxygen in water drops as temperatures rise.



Heavy aeration is what keeps the roots from drowning in aquaculture, so temp is important in this regard as well.

As to higher temperatures necessarily increasing the rate of nutrient transfer, I'm not sure your reasoning is sound - no offense meant. But just because *some* bacterial populations thrive at a certain temperature range doesn't mean that such a range is optimal for all functions of all organisms. Some bacteria thrive in anaerobic conditions as well, but that doesn't mean turning off your air pumps is beneficial for your roots.

Nutrient absorption isn't just a matter of osmotic pressure, either - pH plays a huge role, for instance. The root cells certainly use active ionic forces to move elements through their walls, and lots of factors will play into their ability to do that.

In short, no, root temps between 68-72F are not just for pathogen control. That's an optimal range for root health for a variety of reasons. *steps away from podium*

^^^ This is the brilliant fucking answer I was looking for.

Thanks.

Boylobster, I wasn't sure my reasoning was sound either - so I threw up a thread!

Since my pilot DWC bucket has been going gangbusters with a water temp of ~82ish - it was my best working hypothesis before I pulled out textbooks.

what would make you think that the water dosent need to be below 70 degrees?

For me - I want to know *why* I want a chiller - just being told that I want one is less helpful.

 

[ehole]

so in a few days do you promise to post pics of what your 82 degree water roots look like?

 

[sedate]

Sure.

Kinda shitty camera phone. Sorry.

It seems okay to me. And like I said - I've never seen a plant grow this fast.

To be fair, it does have two airpumps on it.

I had a bitch of a time getting it to root, but once it did, everything has gone better than expected.

This is 10 days into flowering, very lean nutes - maybe 700ppm right now - the foliage is facing away from the camera a bit, the plant is looking at a vert-hung 1000.

EDIT:

Ok maybe 80/day and 70/night?

BTW, I never said I didn't think roots didn't need to be kept cool or that I didn't need to worry about this issue in an RDWC - I just didn't quite get it since it hadn't been fully fleshed out - and my results seem quite satisfactory so far.

So I do appreciate all the input.

 

[Boylobster]

And that's understandable, since you're looking at what you would probably consider a decent counterexample to conventional practice. It seems like you've caught some slight static here, not for the nature of your questions, but for the presentation of them, if I may say so. 68-72F for standing water temperature is considered a given by most people, I think; if you'd started by saying that you're skeptical 'cause you've got a healthy plant in water that may be "too warm", peeps would've understood where you're coming from a little bit better. :)

At any rate, there's nothing wrong with wanting to know the details of *why* something is an accepted practice. The more you know, the more you grow... usually. :D

A cheap digital kitchen thermometer would be an easy way to monitor your water temp at various times. Then, if there are any changes in root health, you'll have some baseline numbers to correlate them with. Apologies if that's too obvious a suggestion, but it's what I used for a long time (and still do, to monitor temps in my clone box). ;)

 

[zoeronerer]

you have ok root growth now ,then one day you wake up ...have pithium and lose thousands of dollars....

sedate the shit will work but eventually because of your high temps u will lose..

and lose hard.....

for these big systems i run em at 65....

friends in indonesia have a 300 acre tomato farm...

they had no problems for some time. temps spiked pith spiked they lost a million dollars in a week...

just cause your getting ok results without a chiller dosent mean you will continue to...

and your quality and weight will go up with more dissolved o2 and a healthier root system...

think of the chiller as saving yer ass ,,,,

its not about what works its about what works best ....

this is either a hobby or a full time job .....
your call....

 

[Juzam]

It is a bit counterintuitive... the plants *DO* seem to grow better at mid 70's water temps (Ever seen an aero cloner take off?) But if you've done this for a while you'll realize how your roots look if you leave something in a aerocloner too long, run a system for a cycle too hot or have a week of temp issues. It isn't if you'll have problems, it's when. Some strains are more resiliant, some aren't (our OG's are the biggest pansy bitches ever, for example.)

So yes, IMO the warmer temp will make the plant grow faster... but you'll get root rot sooner or later if you leave it too hot.

 

[opt1c]

warmer temps for rooting and cooler temps for the long haul; things just DON'T go wrong in rdwc systems with chillers regarding the roots unless you burn them with nutes... without a chiller a lot of different things can and usually will happen... cooler water equals more dissolved oxygen... i think with your bucket and the two airpumps you may be pumping in so much oxygen it doesn't matter how much the water can hold as its getting more than it can use 24/7... again that's just a thought though

i run a sealed room at 85f and i put a chiller on my recirculating rockwool drip setup to keep the plants happy; pouring 80f water on roots does not make plants happy like 70f water

i've been abusing plants with an aerocloner that puts out so much do you really can't rot the roots no matter how hard you try; think a single 8gal tub with an ap20 dedicated to pumping diffused oxygen in the bucket

 

[jointsallday]

Hello opt1c and how are you?

I have been trying to get a q answered and am hoping you will try.

OK - my room,,,-here goes,, 2k hps---50 W/sq ft. ---- lots of air movement---co2 1300-1500

temp 77 --rh 45% or so canopy and wall temp above the shadow line are with 4-5 degrees - - lots of air moving

Q= Does my weed grow better at 77 or 85???
Or is it only more tolerant to 85 temps with co2??

bottom line is Are they happier at 78 or 88??

thanks