Water temps, what is the hottest, what is the coldest, what is the best temp?

pretty simple really, im wondering what are the hottest water res temps for viable growth, whats the coldest temp, and what is the optimal water temperature for growing.

it will be a full deep water, roots fully submerged approx 1 inch from seed, will be using Advanced nutrients, a tea of cyclo organic, jurrassic soluable nutes, and bio root from general organics. the plant will have its own designated air stone, and cool air supply from a raised position, ph will be between 5.5-6 depending on fluctuations, surrounding air temp will vary between 20-22 at night, and 27-30 during the day, air flow all day, minimal-none at night,

i am not sure if that information is important to the water temps but it is there just in case.

also, will different water temps affect nutrient uptake, unwanted growth, root development, ph levels, and anything else you might think is important to know.

Thank you very much RIU

The temp is to control mold. dont think it'll effect nute uptake. Think of the plant living outside. its not always 70"

aight ty

just check em in the am n watch them transform over night. Im in love with dwc atm, first time n pretty crazy growth compared to dirt.

My temps are 29-30 in veg and I only feed at lights on with a water temp of 24-25. That said I have fed at 18-19 but she don't like.

my res is at 65 on the chiller

Ummm I think temps would greatly effect nute uptake but could be wrong. I try to keep temps at or below 70. Sadly I have no mechanical cooling so its an issue. Some people run teas and supposedly are able to keep res's warmer. I have no experience with that though.

Low 60's. A lot of people dont realize how cool the soil is only 12 to 18 inches down.

waterdawg said:

Umedmm I think temps would greatly effect nute uptake but could be wrong. I try to keep temps at or below 70. Sadly I have no mechanical cooling so its an issue. Some people run teas and supposedly are able to keep res's warmer. I have no experience with that though.

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Every hydro nute ive ever used always has a recommended res temp. The temp may not effect the plants ability to uptake nutes, but it can make nutes unstable.

I keep mine below 70, bad things can happen to roots when Temps get too warm and growth can slow if too cold or warm.

You guys want to see something cool?

http://water.usgs.gov/edu/dissolvedoxygen.html

In that article, is a chart that shows the levels of dissolved oxygen vs the temperature readings in celsius.

This is only to show you how much dissolved oxygen increases in correlation to temperature drops.

A high dissolved oxygen content is the key to DWC, IMO.

In my "thinking" wether correctly or not, increasing dissolved oxygen content to your roots, is ALMOST equal to using cO2 on the plants themselves...

Even in soil grows, I try to drill as many hole into the sides of the buckets as the soil will allow(i.e.: not escaping through the holes when I water it), in an effort to provide as much oxygen to the roots as possible. Plus it helps the soil fluctuate between wet and dry cycles a bit more.

BenFranklin said:

You guys want to see something cool?

http://water.usgs.gov/edu/dissolvedoxygen.html

In that article, is a chart that shows the levels of dissolved oxygen vs the temperature readings in celsius.

This is only to show you how much dissolved oxygen increases in correlation to temperature drops.

A high dissolved oxygen content is the key to DWC, IMO.

In my "thinking" wether correctly or not, increasing dissolved oxygen content to your roots, is ALMOST equal to using cO2 on the plants themselves...

Even in soil grows, I try to drill as many hole into the sides of the buckets as the soil will allow(i.e.: not escaping through the holes when I water it), in an effort to provide as much oxygen to the roots as possible. Plus it helps the soil fluctuate between wet and dry cycles a bit more.

Click to expand...

Definitely the more do on any system the better, especially in dwc

In the temp. ranges we use, DO doesn't vary nearly as much as people act like it does. It's a non-issue as far as I'm concerned. Making sure you aerate enough is more important. I prefer 'flooming' my res, and also drop the water through the plant site bucket lids for a waterfall. I don't use air stones at all anymore.

I have my regulator at 68F.

Glaucoma said:

In the temp. ranges we use, DO doesn't vary nearly as much as people act like it does. It's a non-issue as far as I'm concerned. Making sure you aerate enough is more important. I prefer 'flooming' my res, and also drop the water through the plant site bucket lids for a waterfall. I don't use air stones at all anymore.

I have my regulator at 68F.

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Air stones provide greater surface area for dissolved oxygen, they also quiet the agitation in the bucket. IF you have higher temperatures, you should increase the agitation of the water to compensate, however, there is a point of diminishing returns in which water temperatures get to high to deliver dissolved oxygen.

And yes, they do vary as much as people say they do, as (lights on, w/ pumps running) can raise temperatures and (lights off) lowers temperatures.

In the mornings your plants look great and are all happy and standing up and then as the day progresses they start to droop... It is because of the temperature fluctuation steadily raising the temperature of the reservoir and the loss of dissolved oxygen, until (lights out).

Picture the plant as you. I know I wouldn't like to be fed in cold circumstances I.e cold water and food. like I said before I have fed at lowest 18 degrees and they did not like and it slows growth down but I'm sure I will be corrected. I have found best temps for my res work around 24-25 degrees but remember to account at times for variables like temps and water temps. If its summer time and I can't lower my tent temps below 30-32 degrees I make sure my res is just that bit cooler then 25 coz we all know in summer how you feel when its hot out and we consume cold products so same principal for plants,they live like we do. In winter like it is now in Australia I'm sitting on 25 in res and they are loving it.

BenFranklin said:

Air stones provide greater surface area for dissolved oxygen, they also quiet the agitation in the bucket. IF you have higher temperatures, you should increase the agitation of the water to compensate, however, there is a point of diminishing returns in which water temperatures get to high to deliver dissolved oxygen.

Click to expand...

I've found that watt vs watt, a powerhead aerates better than any airstone and is much cheaper to setup and operate in the long run. I'm not the only one that doesn't use airstones. Airstones are a PITA. They also dump a ton of heat into the water. Go ahead and measure the output air temp yourself, you'll see. It can and will go over 100F. A powerhead shooting water straight up like a small fountain or across the surface of the water will easily match or exceed surface turbulence compared to airstones, which is where the vast majority of oxygen exchange takes place. The only catch to flooming is you should do it in a res, not the grow buckets.

BenFranklin said:

And yes, they do vary as much as people say they do, as (lights on, w/ pumps running) can raise temperatures and (lights off) lowers temperatures.

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I was talking about the variance of max DO based on temps, not temp fluctuations throughout the day. Many of us insulate and chill our buckets. Many people parrot the claim that lower temps = more DO, when in reality, it doesn't make that much of a difference. People here have grown with water temps in the 90's just fine with the addition of beneficial bacteria.

At sea level pressure:
65F, fresh water will hold 9.4ppm of DO
75F, fresh water will hold 8.6ppm of DO

That equates to about a 1% loss of max DO per 1*F rise in the ranges most people run.
Proper, fast aeration is more important than max DO.

I personally like 68F. Less chance of slime. But mid 70's seems to make the roots happier in my experience. I just don't like fussing with teas anymore. I'll toss in some biozyme or use fish tank water as the base now, but I have many gallons of fish, so that's not an option for everyone. Doing that, plus 68F is the lazy, trouble free sweet spot for my setup.

Glaucoma said:

I've found that watt vs watt, a powerhead aerates better than any airstone and is much cheaper to setup and operate in the long run. I'm not the only one that doesn't use airstones. Airstones are a PITA. They also dump a ton of heat into the water. Go ahead and measure the output air temp yourself, you'll see. It can and will go over 100F. A powerhead shooting water straight up like a small fountain or across the surface of the water will easily match or exceed surface turbulence compared to airstones, which is where the vast majority of oxygen exchange takes place. The only catch to flooming is you should do it in a res, not the grow buckets.

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To argue the point, I use double outlet Hydro-farm air-pumps, I also use one other 4 way, not sure what brand, it's been nice to me for the past 2 years.

The hydro-farm air pumps, i've never had a problem with ever, I've used them for years and years and years as fish tank pumps.

I have at least on Hydro-farm air pump that is 5 years old currently, that took a big drink of water after it back flowed and water got into the pump, it got a little loud for a bit, but then I resealed the cord with some putty filler I don't recall and now that has run great like that for about 3 years.

Now, I am not saying that your power head is not the best route to go, for YOUR grow it is, or you wouldn't use it. That's not beneficial to my grow, so I don't. I find the large air stones that are heavy enough to weigh themselves down are the best option for me.

On top of that, let me take 1% of something you need that's vital to life, like oxygen, and see if you thrive, or only grow "ok".....
Also on top of that, the temperature change in the bucket is also effecting more than just dissolved oxygen content, it's also effecting your PH.(but, that's another issue, though related)
Nothing in farming is an exact science, unless you make it. Everybody has their own ways and methods, some work great for one while another not so great.

By the way, I get slime as well at 71-5 degrees, if I let the buckets evaporate off to much. Seems to be a common threshold. I hate it... =) Thankfully I grow in a nice underground room.

BenFranklin said:

Nothing in farming is an exact science, unless you make it. Everybody has their own ways and methods, some work great for one while another not so great.

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True that! Individual variables can make a quite a difference. I enjoy the basic science behind it and always aim for the most cost efficient grow possible, from all angles.

As they say.. your mileage may vary. =)

Glaucoma said:

In the temp. ranges we use, DO doesn't vary nearly as much as people act like it does. It's a non-issue as far as I'm concerned. Making sure you aerate enough is more important. I prefer 'flooming' my res, and also drop the water through the plant site bucket lids for a waterfall. I don't use air stones at all anymore.

I have my regulator at 68F.

Click to expand...

I floom as well, basically my roots sit in a river lol. I use a pump that hits the top of my plant tray and splashes every where and the water is kept at 6" deep falling back to lower res creating a huge waterfall as well. My pumps run 24/7 and the plants love it (I think lol). Also when I do a res refill the water temp is low fifties and again I think the plants like it, they just keep on going and dont miss a beat.

I would love to flume if I had the room! Believe me, if I had another 2 foot to my ceilings... I'd have ebb and flow or aeroponics set up.