RDWC w/ Chiller vs Bubbler, Why is bubbler (apparently) winning?

Takeshy

Takeshy

Well-Known Member
Hello!

I am currently running 2 grow tents at the moment:
  • one RDWC System with Chiller (water temperature: 19-20ºC):

  • and one DWC Bubbler System (water temperature: 27-28ºC):


The interesting is that the bubblers actually have a better root system so far:
  • RDWC System with Chiller:

  • DWC Bubbler System:


Both tents have the same ambient temperatures (they are in the same room), have the same nutrient feeding, same strain, same water level (distance from netpot) and same light.
They also have the same air pump but the RDWC system should have more oxygenation in the water.

The only variables I see in both systems is water volume, temperature, and oxygenation. Everything else is basically the same.

Why is the bubbler (apparently) winning?
 
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zypheruk

zypheruk

Well-Known Member
The bubbler is winning because the nutrient temps are a little warmer which is what the plants actually like and will grow faster as a result, but more prone to rot. With the chiller we are running at lower temps to keep things in check but also slows things down.
 
Airwalker16

Airwalker16

Well-Known Member
Takeshy said:
Hello!

I am currently running 2 grow tents at the moment:
  • one RDWC System with Chiller (water temperature: 19-20ºC):

  • and one DWC Bubbler System (water temperature: 27-28ºC):


The interesting is that the bubblers actually have a better root system so far:
  • RDWC System with Chiller:

  • DWC Bubbler System:


Both tents have the same ambient temperatures (they are in the same room), have the same nutrient feeding, same strain, same water level (distance from netpot) and same light.
They also have the same air pump but the RDWC system should have more oxygenation in the water.

The only variables I see in both systems is water volume, temperature, and oxygenation. Everything else is basically the same.

Why is the bubbler (apparently) winning?
Click to expand...
Could be the clones that were taken are just stronger rooted too. I think once you flip to flower, you'll see the chiller side take off
 
Takeshy

Takeshy

Well-Known Member
Airwalker16 said:
Could be the clones that were taken are just stronger rooted too. I think once you flip to flower, you'll see the chiller side take off
Click to expand...
They aren't clones, they germinated from seed.
The plants in the RDWC system actually were faster at the germination/propagation stage. So genetics should be also in the RDWC side.
 
Airwalker16

Airwalker16

Well-Known Member
Takeshy said:
They aren't clones, they germinated from seed.
The plants in the RDWC system actually were faster at the germination/propagation stage. So genetics should be also in the RDWC side.
Click to expand...
Oh from seed you can't do a true side by side mate
 
GBAUTO

GBAUTO

Well-Known Member
zypheruk said:
The bubbler is winning because the nutrient temps are a little warmer which is what the plants actually like and will grow faster as a result, but more prone to rot. With the chiller we are running at lower temps to keep things in check but also slows things down.
Click to expand...
When I looked at dissolved oxygen concentration versus temperature plots, it looks like there is about 12-14% decrease over 70-80 degF. I agree with zypheruk that the real challenge is preventing any funk from growing in the solution. Beneficial microbes made all the difference for me.
 
Airwalker16

Airwalker16

Well-Known Member
All he's doing is pulling the water through the system on the RDwc. If he had a manifold teeing off to each bucket for a waterfall, I bet you'd see a large improvement.
 
Keesje

Keesje

Well-Known Member
The reason is the water temperature. Nothing else.
Roots like a higher temperature. In cloning, veg and flower stage.

Amount of DO available for the plants will be about the same, despite the difference in temperature.
 
Airwalker16

Airwalker16

Well-Known Member
I definitely disagree. The mini system runs about 73-75*F and it's slow going with the usual crispy leaf but once they're in the tent with chilled water to 66, they absolutely explode.
Rooting clones in an aerocloner I will have to agree with though. They like warmer water for sure.
 
Keesje

Keesje

Well-Known Member
Airwalker16 said:
but once they're in the tent with chilled water to 66, they absolutely explode.
Click to expand...
Perhaps that is your experience, but why do commercial hydro growers never use a chiller then?
They don't care that the water heats up.
Even during hot summers they do not use anything to cool it down.
On the contrary; during winter time they make sure that the bassins in their greenhouses have a higher temperature. At least 70 degrees.
 
Takeshy

Takeshy

Well-Known Member
zypheruk said:
@Takeshy have you any updates on how things are going?
Click to expand...
I turned off chiller. I already defeated pythium with hydroguard and I also have lots of air in each bucket. There is simply to reason for me to have the chiller running. Its a waste of electricity.

The plants in heated water grew faster than plants with cold water. Yes, cold water hold more DO and is ideal to slow down pythium growth but in the other hand plants don't like it. So why to use it then?

Most growers and web-sites you see all over the web will recommend you to buy a chiller when growing hydroponically which is actually a bad advice IMO.
 
zypheruk

zypheruk

Well-Known Member
@Takeshy I have a chiller used for 3 months since new sitting in the loft taking up space and providing me with just an empty wallet. Currently have a test plant this last 3 weeks sitting in hydroton with nutes being pumped on it every two hours for 15 minutes, nice healty roots and its only getting grow nutes, the temps of the water is 24c . Not dwc granted, but working. I change out the solution every 7 days and ph to 5.5 and don't look near it tell next change. I will let the roots go down now into the bucket and see how using one little pump with a venturi on it works out in dwc. If it kicks the bucket it kicks the bucket.
 
Keesje

Keesje

Well-Known Member
Takeshy said:
Most growers and web-sites you see all over the web will recommend you to buy a chiller when growing hydroponically which is actually a bad advice IMO.
Click to expand...
Because especially in the growers world there are a lot of parrots.
Some things got stuck in their mind, but they have no clue why someone at some point came up with an idea.

For example...
Cold water can contains more DO then warm water. Although by itself is true, there is no need provide your roots with cold water and thus more oxygen. Once you move the water just a little bit, there will be new DO in the water. Enough for the plants.
Cold water is better for roots. False, roots like warmer water better. They will grow faster, bigger, better. As well will Pythium. So you will have to find a balance.

Always look at what professional greenhouse business people do. They don't use chillers, because it is not needed, it is too expensive and it is another machine that can break down. They even don't look too much for the amount of DO in their water. They will pump it around for 5 minutes every hour, and that's it.
 
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