Water chiller a necessity ?

Osulax2131

Active Member
GH waterfarm 8 pack
Lights - 2 x Optic 4s
4x8 room
No co2
Greenleaf Nutrients Megacrop
CXHydroponics Regenaroot and Wiltguard


I’ve only done a few DWC grows years ago and never used a water chiller. It seems like most people are using them now a days. If my room isn’t putting off a ton of heat can I get by with out one ?

What are the ideal water temps? What are considered high temps for water that could hurt the roots ?
 

Airwalker16

Well-Known Member
GH waterfarm 8 pack
Lights - 2 x Optic 4s
4x8 room
No co2
Greenleaf Nutrients Megacrop
CXHydroponics Regenaroot and Wiltguard


I’ve only done a few DWC grows years ago and never used a water chiller. It seems like most people are using them now a days. If my room isn’t putting off a ton of heat can I get by with out one ?

What are the ideal water temps? What are considered high temps for water that could hurt the roots ?
If your WATER Temp doesn't go above 70*F, Then you won't need one
 

GBAUTO

Well-Known Member
I've been growing RDWC for the past 3 years. Rez temps are ALWAYS in the 70's, sometimes reaching the lower 80's on scorching days. I use either Hydroguard or GFF as an innoculant in my rez. While I agree that lower temps do have a benefit I have to disagree that they are necessary.
 

Failmore

Well-Known Member
I've been growing RDWC for the past 3 years. Rez temps are ALWAYS in the 70's, sometimes reaching the lower 80's on scorching days. I use either Hydroguard or GFF as an innoculant in my rez. While I agree that lower temps do have a benefit I have to disagree that they are necessary.
there is less dissolved oxygen in the water at 80F tho. That is why it is important to keep the temps down. (https://www.fondriest.com/environmental-measurements/parameters/water-quality/dissolved-oxygen/). From the graph it seems like about a 20% difference between 68f and 86f. It will not kill the plant but your not providing the best living conditions for it. It is not required but keeping the water temps low is highly recommended. I was not able to control root rot with hi water temps using hydroguard. Maybe i was some how fucking up applying hydroguard but i don't know if that is possible. I had to start using frozen 1 liter bottles and h202. Luckily it is now winter and water is 68-69 with no ice bottles.
 

GBAUTO

Well-Known Member
Agreed. I think that there is about a 10% decrease in DO from 68degF to 78degF.
I don't have an answer as to why I'm able to run my system at the temps it does and others have issues. Just saying that it has been working for me. Optimizing environmental conditions improves yield but I'm not willing to spend money unless I absolutely need to do that.
I spend my money on lighting and rudimentary climate control. I find that lighting has the biggest impact and then trying to provide an acceptable VPD to promote growth is a close second.
 

5BY5LEC

Well-Known Member
Buy one and you won't have to find out. Your questions about root temps....there are so many variables. One guy will get the shit at 70....one guy is fine at 90. Just get a chiller.
 

herballuvmonkey

Well-Known Member
Or you can get 3L bottles of water and freeze them. Use one per every 5 gallons in your res guaranteed to keep your temps below 70 overnight. Change daily.
 

Renfro

Well-Known Member
Agreed. I think that there is about a 10% decrease in DO from 68degF to 78degF.
I don't have an answer as to why I'm able to run my system at the temps it does and others have issues. Just saying that it has been working for me. Optimizing environmental conditions improves yield but I'm not willing to spend money unless I absolutely need to do that.
I spend my money on lighting and rudimentary climate control. I find that lighting has the biggest impact and then trying to provide an acceptable VPD to promote growth is a close second.
I also ran a DWC without a chiller and got some good results without a chiller even despite temps in the 78 - 80 degree range. That said I think it had a lot to do with strain. Some strains wouldn't last and Kandy Kush would. I was also using Orca at the time.
 

Aqua Man

Well-Known Member
DO is not something I would consider an issue with temps under mid 80's if you have adequate gas exchange. It is true cooler water hold more DO and will provide a bigger buffer range for replenishment.

The ideal root temp for growth is around 77f but also ideal for bacteria, fungus and other nasties like pythium.

If you go sterile and stay on top of it or run a live system with a healthy population beneficial bacteria there are no issues running higher temps. BUT!!!!!! At those temps understand that if something go wrong it will go wrong fast. So cooler temps that reduce the metabolic rate are often desired to keep reproduction of bad bacteria, fungus and other nasties like pythium slow and usually gives enough time to react and treat.

Also temps over 77-78 start to slow growth much more rapidly as it increased as compared to cooler than 77-78
 
Last edited:

Keesje

Well-Known Member
there is less dissolved oxygen in the water at 80F tho. That is why it is important to keep the temps down. (
When you have a good gas exchange, it does not matter much if the water holds 8 mg/liter or 9 mg/liter.
The moment your roots use some DO, new DO will get into the water immediately and maximum levels will be reached in an instant.
It is a never-ending supply.

Of course all within certain limits: A lot of roots, high temperatures, a small watersurface > not good.
 

Jimdamick

Well-Known Member
Just use air stones in your bucket to supply added O2.
No need for a chiller unless your water goes over 80 degrees, then there might be issues.
 

Logan Burke

Well-Known Member
Yeah I'd say waterfalls would be better for anyone trying to avoid temps warm enough to need a chiller. If you can use airstones without too high of a temp then they definitely work. Waterfalls will create more DO, but air stones have always been sufficient enough to get the job done for me...I'd like to do waterfalls if I do a recirculating system in the future though.
 

StinkBud

Well-Known Member
Water temps usually stay around 10 degrees lower than the air temps. Below 68 is best so if you can keep your room below 78 you can usually pull it off.
Bacteria have a hard time surviving cold temps. That's why we have refrigerators (duh). Chillers are an easy but expensive solution to reduce the chance of "the funk".
You can also mix 28 grams (1oz.) of pool shock into a gallon of water. Now add 1ml of solution for every gallon of water in your res. Presto! No more funk!
 

ttystikk

Well-Known Member
Waterfalls were the ticket for me. With them, it didn't matter what the water temps were. Without them, I had to ensure temps dropped into the mid 60s at least once every 24 hours.

I took this to mean that good circulation and aeration with waterfalls were better all around than airstones because the crutch of water chilling wasn't needed.

Chilling water costs energy, which costs money. If it isn't necessary then why do it?
 

DaFreak

Well-Known Member
Leave an air-gap of two inches below your net pot if you don’t use chiller. Just extra protection.
 

ttystikk

Well-Known Member
Leave an air-gap of two inches below your net pot if you don’t use chiller. Just extra protection.
With a waterfall system, the splash would keep the bottom of the netpot and exposed roots wet. This meant that the plants didn't care what the water level is as long as the netpot is above the water level.
 
Last edited:
Top