# Reservoir temperature required



## Jimmy Luffnan (Sep 20, 2009)

Have a recirculating system, but I live in a climate that does not favor hydroponics and likes to develop root diseases if the water becomes too warm...

Apart from nutrient additives, I would like to lower the reservoir temperature with a water chiller and hopefully raise DO levels at the same time...

So how low can I drop the water temperature before the roots suck their roots up out of the water like a set of nuts getting in a bathtub full of ice water...?

Any additives you know would also work well for my situation would be appreciated also...

Cheers.


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## grobofotwanky (Sep 20, 2009)

When I grow hydro I usually keep my res at about 62F. I'm able to accomplish this with frozen water bottles due to the smaller size of my res. There are top notch chillers http://www.wormsway.com/results.aspx?t=prod&search=chiller&cat=all&AC=1 or if you like DIYs I found this the other day. Pretty good read. https://www.rollitup.org/grow-room-design-setup/208004-diy-do-yourself-water-chiller.html
I've heard that hydrogen peroxide wards off root problems in hydro but it may just be heresay.


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## smppro (Sep 20, 2009)

68 is ideal, have you had root problems yet? I run synthetic nutes in a constantly circulating hydro tower, outside temps are 95, water temps are 85+, plants grow like crazy. you can also look for products like sm-90, aquashield, hygrozyme. Frozen water bottle work you just have to always change them.


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## Jimmy Luffnan (Sep 20, 2009)

Cheers both of you for your posts... and I seem to gather that 69F is the best temperature I believe... kiss-ass

I haven't had any root issues of yet, but I have seen many aborted grows because of issues...

If 69F is the optimum... what would the absolute minimum be?

I know the problems associated with water temps being too high, any negative impacts of having it too cold... and I don't mean ice blocks! 

I mean more so root shock etc.

Cheers.


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## Illegal Smile (Sep 20, 2009)

Below 65 can slow growth.


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## Roseman (Sep 20, 2009)

*Temperatures, Humidity* 
permalink

The temperature is the hardest factor to take control of to me. When confined to a small space, ballasts and lights can push temperatures sky-high in no time flat. That is why I use CFLS, to avoid venting heat. This is especially true during hot summer months when outside temperature reaches its highest. Nighttime (LIGHTS OFF period) temperature can be just as difficult to regulate during cold winter month. Most gardeners are aware that temperature in the grow room plays a major role and can greatly affect the growth of plants and the quality of the finished crop. Most gardeners do not know how controlling the temperature of their garden in very specific ways they can achieve a superior crop. Drift to far from these ideal temperatures and watch your plants and crop suffer. 
Before getting started it is highly recommended that every indoor garden has a max/min thermometer. *(Digital $4.95 at Walmart)* 







This product allows the gardener to see exactly the fluctuations in temperature within their garden. Without this useful tool there is no accurate way of knowing the different temperatures between daytime (lights on) and nighttime (lights off). *The difference between the two temperatures is very important to plant growth.* Anymore than a 10F-15F difference between daytime and nighttime temperatures and you risk shocking and stressing the plants. You want a 10 degree difference between LIGHTS ON and LIGHTS OFF temps. In general the optimal daytime temperature for plant growth is between 70F -75F. Drift to far above this range or too far below and growth can be severely affected. Daytime temperatures exceeding 90F or under 62F and plant growth will be slowed and stunted. Plants do thrive in afganastan's 110 degrees, but they quit growing at that temp. If the temperature drifts higher than 95F the plant&#8217;s enzyme production will drop off and the plant will begin shutting down. At temperatures above 92 - 94, high photosynthesis shuts down due to the stomata in the leaves closing down to conserve water. At normal temperatures the stomata will be open, taking in CO2 and sweating water to keep the plant cool and allowing for transpiration. 
Ideal temperature varies depending on whether or not CO2 is being introduced to the environment. A more suitable daytime temperature when the air is being enriched with CO2 is 80F-85F. This temperature range promotes the exchange of gases between the plants and the environment. Also, it can speed up the process of photosynthesis. Plant in an environment at 86F can perform carbon extraction from CO2 twice as fast as at 68F. It is still recommended that the nighttime temperature drop no more than 15f from that of the daytime temperature. There is another relationship between temperature and the absorbsion of gases by plants that many hobbyist growers are aware of. That is the relationship between the temperature of the water in your reservoir and the amount of oxygen the water can hold. *The best range that your reservoir can be between is 60F-75F. Ideally the reservoir temperature should be at 65F because this level contains the most oxygen.* Also this temperature will help control transpiration (the act of drawing up nutrients by evaporating water through out the leaves), and humidity levels. Buying a simple aquarium floating thermometer will allow you to know where you fit in this range. 








$2 to $4 at Walmart, Target, 
PetSmart Aquarium Dept





Another great reason for regulating the temperature in your grow room is that biological processes can be speed up exponentially by every degree. This is true for your plants as well as the potential pests that may invade your grow room. 
*Pests such as spider mites can reproduce up to 10 times faster with every degree the temperature rises.*
These pests can destroy a garden in no time flat, you really do not want to make it any easier for them. Spider Mite Eggs and webs can screw up the buds so bad, they can nto be smoked. With a daytime temperature at a steady 72F and nighttime temperature of 65F it is much easier to control and destroy spider mite, thrip, and many other pest populations. 
The same principal can be applied to the prevention and control of fungi, molds, mildews, and bacteria, which can spread more rapidly when temperatures in the grow room or reservoir exceed 90F. Also, the warmer the air, the more water it can retain which means humidity levels can easily go beyond the recommended 40-50% for Vegging. (you want high humidity for VEG, and low humidity for Flowering.) This high humidity coupled with lower nighttime temperatures can cause condensation to form on leaves. This will invite molds, mildews, fungi, and bacteria to take over you grow space. With high temperatures the likely-hood of losing control of the problem, such as powdery mildew, is very high. Once control is lost your plants may be the next to go.

Temperature is also very important when it comes to starting seeds and getting cuttings to root. Placing seedling trays on a heating mat will reduce germination time dramatically. Speeding up germination time usually leads to stronger and healthier plants. Also, less time spent between crop cycles makes a garden efficient. More harvests provided in less time can equal big bucks in the pockets of professional growers. 
The ideal temperature for sprouting or cloning is 80F. Any higher and you risk burning the roots. Also, many seeds simply will not germinate at temperatures over 90F. The seeds will become dormant and never sprout. 
The same principal used for seeds is used on cuttings to coax roots out quicker. The sooner cuttings can establish roots the better. If roots can be forced quickly they will grow strong and stay strong. A bottom temperature of 80F-85F, roughly 10F warmer than the air, will speed up rooting time and help to jump start those roots once they do begin. Let the temperature get too high or too low and roots growth will be hindered or they will never grow at all. Using the proper technique and the proper temperature for bottom heat not only can rooting time be speed up from 2 weeks to as little as 3 days, but the survival rate of your cuttings will drastically improve.

On the topic of roots, there is an ideal temperature for the root zone after the plants&#8217; roots have been established. Roots are working 24 hours a day and constant attention is required concerning temperature in and around the root zone. The ideal temp for this root zone is generally 65 to 75 degrees F. At this temperature the ion exchange between the roots and the environment around them is at its absolute best. This means that the plant&#8217;s root system can take up more macro nutrients, more micro nutrients, and more oxygen at this temperature than at any other level. This makes a plant more efficient and a plant working efficiently will provide a superior yield.

Amazingly, some growers grow successfully with no themometer for the air or water. But for maximum efficiency, you got to take control of temps.

HUMIDITY? that is more simple to me. Get the Humidity VERY high for VEGGING, and very low for FLOWERING. 

in Vegging, I mist them daily. I do raise the lights up, to be careful with my bulbs getting wet and breaking. And when it rains outside, it also gets cloudy and the sun's rays are blocked. Plants in outdoors, in nature do get an ocasional rain shower or thunderstorm. Do you let it rain on yours? I do, but artificially by MISTING.
AND, I bought a cheap humidifier.

Cheap Cool Mist Humidifiers from Walmart:

 $26.00 


 
*Ultrasonic Humidifier With Light*


*$28.97 *



** *Graco, Cool Mist Humidifier, 1.5 Gallon **$29.96 *




During Flowering, we need a low humidity, especially to avoid Bud mold and bud rot.


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## Roseman (Sep 20, 2009)

More Cooling Tips. 

Insulate the reservoir with towels or blankets.

Cover the lid with something wet.

Put the air pumps where the Lights do not shine on them or heat them.

To get the temp down and the humidity up, try these:

You need a fan pulling heat out and a fan pulling cool air in.
You have to have an oscilating fan on the plants.
Lay wet *rolled up like a cigar* wash rags everywhere.
Hang a soaking wet bath towel on a cloths hanger and let it drip into a pan or bucket.
Put a frozen milk jug of water in front of a fan or let it drip into something by putting a pin hole in it. 
Get a bucket, put ice in it or frozen water and blow a fan into the bucket, blowing cool air everywhere. And you can put Pine Sol or ONA in the bucket for Odor Control.



Put saucers and cups of water everywhere.
Mist the plants with plain pH water.
Put Frozen cups of water on the lids and everywhere around the plants.


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## Roseman (Sep 20, 2009)

a RIU member named Dystopia wrote this:

First, insulating your res really helps stabilize the temps. Wrap mylar or insulation around it; I build my reservoirs out of ice coolers (attachment 1).

I used to put blue ice bags in the res if the temps started to rise, but I can no longer recommend putting ice in the root zone. During my last grow I did this, and the plant closest to where I put the ice definitely didn't like it; it ended up stunted and there was a bald spot in the root zone where the ice went. And as the root mass grows there's generally not enough room to stick ice bottles in the res anyways.

If you want to use ice to cool the res you might want to try the following ideas:

1. I jury-rigged some quart and half-gallon jugs using drip line and a drip-line shut-off valve (attachment 2). What I do is freeze them overnight and then stick the line in a hole on top of the res in the morning (attachment 3). This serves a few purposes: 1) provides a slow flow of cold water to the res throughout the day, so the roots aren't shocked by a rapid change in temperature; 2) keeps the res topped off; and 3) serves as a ghetto A/C for the grow area. The main disadvantage is condensation; I have to keep a rag under the jug to soak up water.

2. I built a semi-recirculating DWC for my latest grow (water pump is on a timer). Basically, I have a separate reservoir that is connected to my plant reservoirs via plumbing and a pump. I'm doing this for several reasons: 1) one thing I hate about DWC is that you generally have to lift the lid to do any maintenance in the res - a separate res allows you to easily do maintenance without disturbing the plant reservoirs; 2) I'm planning on doing a ScrOG - once the plants are in the screen lifting the lids becomes problematic; 4) more water means that things like temperature, ph, and nutrient concentration are more stable; and 3) if I need to cool the reservoirs I can put ice in the shared res without worrying about the roots. The main disadvantages are complexity, size of system, and more nute usage.

Some other ideas:

1. Put your air pump in a cool area. It seems like most people put their pump on top of the reservoir under the lights. If it is hot where you put the pump, then you're going to be pumping hot air into the res. I try to put mine outside the grow area if possible, or as close to the inlet as possible.

2. Direct some airflow from the inlet over the res using a fan.

3. If you use a humidifier like what Roseman recommends try directing the air from the outlet over the res using a fan. Acts kind of like a swamp cooler; I've found it lowers the temp over my res by about 5*.

4. Running a water pump continuously in the res will cause the temps to rise. I think I have a good idea how the stealth hydro system works, for instance, and I can certainly see the advantages of it during the early stages of growth. However, once the roots are in the water I'm not sure if running the pump continuously is necessary - maybe one of you users can help me out. If it was me, I would put the pump on a timer and run it kind of like an ebb and flow once the roots are in the water - like for 10 minutes 5 times a day - IDK.

Of course, like Roseman says, the best way is to keep your room temp down if you can. 75* is out of the question for me, it costs too much to keep my A/C running all day at 70*, especially since no one's home anyways. I keep my A/C at 80*, and my grow room at 85*.
Attached Thumbnails


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## Jimmy Luffnan (Sep 20, 2009)

Thanks Illegal Smile... and thank you Roseman

I actually went through and bookmarked you post you have put previously last night Roseman... great post and thankyou!

Im all for great ideas.. so keep them coming 

My mind was leaning toward this item...

http://www.nanoreefsupply.com/index.php?aquarium=chillers_cw

... as I only require a small res... and this comes with additional probes if I go bigger... and temp monitor


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## DenseBuds (Sep 27, 2009)

Jimmy Luffnan said:


> My mind was leaning toward this item...
> 
> http://www.nanoreefsupply.com/index.php?aquarium=chillers_cw
> 
> ... as I only require a small res... and this comes with additional probes if I go bigger... and temp monitor


I would eventually like to move into aeroponics but the res temp has stumped me. I don't want to spend > $150 on a "big" chiller and have to worry about plumbing it to my res. This sounds perfect if it works. I imagine my res would only be 5-8 gal anyway. Please post your results if you do get it.


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## Jimmy Luffnan (Sep 27, 2009)

DenseBuds said:


> I would eventually like to move into aeroponics but the res temp has stumped me. I don't want to spend > $150 on a "big" chiller and have to worry about plumbing it to my res. This sounds perfect if it works. I imagine my res would only be 5-8 gal anyway. Please post your results if you do get it.


No probs.. will do


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## Dapps420 (Sep 28, 2009)

Roseman said:


> More Cooling Tips.
> 
> Insulate the reservoir with towels or blankets.
> 
> ...




Hey man, that was brilliant! I was having humidity/ temp issues, I installed an air duct connected to my central air and hung two soaking wet towels and my humidity jumped from 21% to 47% in about two min. Alos my temp is officially down from 87degrees to 79Degrees


THANKS A BUNCH!


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## Roseman (Sep 29, 2009)

Dapps420 said:


> Hey man, that was brilliant! I was having humidity/ temp issues, I installed an air duct connected to my central air and hung two soaking wet towels and my humidity jumped from 21% to 47% in about two min. Alos my temp is officially down from 87degrees to 79Degrees
> 
> 
> THANKS A BUNCH!


I just love to hear good reports like that one.


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## DonaldJTrump (Jan 5, 2017)

my rez is 60-62 in the winter. big deal? cant see much of a difference....


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## J Henry (Jan 8, 2017)

Hey Jimmy,
Actually DWC fugal outbreaks do not occur with healthy plants and microbial eco systems. Fungi are ubiquitous, opportunist that thrive on dead, decaying organic matter… dead and dying people, plants, roots and Beneficial microbes in DWC. Fungi are like turkey buzzards, they are always around, and congregate for the feast after death… fungi clean up sickly dead stuff and thrive in hypoxic, low oxygen environments.

So you think low oxygen is killing your roots, inviting fungal out breaks or do you know you have a low oxygen problem and just “hoping” you can correct low oxygen issues with a water chiller? That is a popular idea promoted by water chiller salesmen.

Before you spend more of your hard earned money shooting in the dark, hoping and praying for solutions your fungal outbreaks, *have you ever actually tested your res DO Saturation, actually identify that you do have a low DO problem or are you guessing, you might have a low DO problem?*

Have you ever tested your DO Saturation with a DO Meter or DO chemical test strips?

If you have tested the res DO Saturation, what is your DO Sat?

If you have not tested your DO Sat, why not test it and see if low DO is really your problem?

*The big question is --- what DO Saturation do you really want to maintain 24/7 through-out months of your grow period?*

Consider this: You must insure minimal safe oxygenation for 2 eco systems (plant and microbial systems) 24/7 for months to insure healthy plants and healthy thriving Bennies. If you can’t insure minimal safe DO Saturation continuously, death, dying and fungal infestations are predictable, you will have more failures and disappointments.

If you will test your res water and discover that you have a low DO problem – providing more oxygen continuously is the quickest and most direct method of correcting all low DO problems.


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## Jonstipated (Jan 8, 2017)

I'm trying something.. I ran an air line from a pump in my basement to an air stone in my res, in hopes that the colder basement air would help keep the temp in the res down. The air line does travel a good 15 feet in warmth before it reaches the res, though, so I'm trying to think of a cheap way to insulate it. I only set this up an hour ago, but if I notice any improvement I have 2 airstones and the drip ring which could all be fed from the basement. 

I have some copper tubing laying around, I want to replace a section of air line with a small coil of that, and place it in a cooler with frozen water bottles. I'd rather not have the bottles in my res. My res doesn't run hot, anyways, I was just trying to think of ways to have more control over the temperature without buying a chiller.


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## Johnny Lawrence (Jan 9, 2017)

J Henry said:


> Hey Jimmy,
> Actually DWC fugal outbreaks . . .


You do realize that the rocket scientist who posted before you bumped a long-dead, seven year old thread, and that "Jimmy" isn't likely to even see this, right???


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## cannn (Jul 20, 2017)

Johnny Lawrence said:


> You do realize that the rocket scientist who posted before you bumped a long-dead, seven year old thread, and that "Jimmy" isn't likely to even see this, right???


Who cares. I saw it. I learned something.


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