Ideal root temperature

[yan]

When using heating mats etc. what’s a good temperature to set the thermostat to when measuring with a probe at the bottom of the pot? 

[latigid aikon]

Mine is set to 26ºc lights on and 23ºc lights off with the probe, as you say, right at the bottom of the pot.

[yan]

Thanks @latigid aikon  I’ll go for the same. Sounds nice and cosy. 

 

[Clubs]

5 hours ago, latigid aikon said:

Mine is set to 26ºc lights on and 23ºc lights off with the probe, as you say, right at the bottom of the pot.

That's interesting. Is that to mimic what happens in nature?  Have you noticed any improvements doing it this way. I'm not sure my Inkbird is capable of this though.

[latigid aikon]

1 hour ago, Clubs said:

Is that to mimic what happens in nature? 

I just figured I could save a bit of electricity when the lights are off and they're not actively photosynthesising.

 

It's an Inkbird I'm using to do that, only the wifi version can do it though.

[Yosser Hughes]

Tropical  for best results

[Goodbloke]

Been using 24.5 fixed. The inkbird for the heat mat is non WiFi, so single time period only. 

I use the dual time wifi model to control air temp, have been playing with this each run to see the effect on stretch. 

[Military Grade]

I set mine to 24c and have the probe 2/3rds drown from the top, Having it right at the bottom is not optimal.

 

But since getting tube heaters either side of the pot the heat mat never turns on unless i'm watering

[yan]

1 hour ago, Goodbloke said:

 

I use the dual time wifi model to control air temp, have been playing with this each run to see the effect on stretch. 

What effect on stretch have you found? Is it possible to reduce it by controlling the temperature difference from lights on to off?

[Slippy One]

1 hour ago, Military Grade said:

 

 

But since getting tube heaters either side of the pot the heat mat never turns on unless i'm watering

I have my heat mat (20w) on constant, the Inkbird controls the tubes only.  

[latigid aikon]

1 hour ago, Military Grade said:

I set mine to 24c and have the probe 2/3rds drown from the top, Having it right at the bottom is not optimal.

If the probe is higher up the pot the bottom gets MUCH hotter than the set temperature before that heat reaches the probe. Why don't you think it is optimal?

[Axiom]

2 hours ago, Goodbloke said:

Been using 24.5 fixed. The inkbird for the heat mat is non WiFi, so single time period only. 

I use the dual time wifi model to control air temp, have been playing with this each run to see the effect on stretch. 

 

Wasn't aware there is a Wifi model. Might check it out. Can do time scheduling? or you set manually every night/day??

 

Just now, latigid aikon said:

If the probe is higher up the pot the bottom gets MUCH hotter than the set temperature before that heat reaches the probe. Why don't you think it is optimal?

 

I had the same idea for like a year until my cogs started turning about it haha 

 

@yan I set mine to 31c at the bottom and use a IR thermometer gun to make sure I'm in a good range (above 22c) from top to bottom. 
As for stretch I noticed that plants go ape shit during veg and produce long stems and reach towards the light more if it's at a distance. 

Flowering effects are less noticeable, but I get the feeling that they are happy about it and it doesn't hurt the ambient temps.
In short - I'd rather spend the money heating roots AND the room optimally, than just heating the ambient air for no reason while root uptake limited.

 

[murphyblue]

Got mine set at 24c with probe about inch and half off the bottom of the pot.

Zip tied it to a bamboo to get the same depth everytime i remove it and put it back in works fine.

 

[yan]

Thanks for all the responses to this.
I asked as I was concerned that the roots in my small pots inside a little veg tent were getting too warm. 
With the heated propagator base and a small tube heater in there it was around 26-27 with the probe at the bottom. 
Based on what you guys are doing it sounds like they will be fine. 

[Military Grade]

7 hours ago, latigid aikon said:

If the probe is higher up the pot the bottom gets MUCH hotter than the set temperature before that heat reaches the probe. Why don't you think it is optimal?

Because if the probe is at the bottom the rest of the upper pot doesn't get to temperature, that's why it's recommended to have it ⅔ down and set it to 24c, this way the bottom of the pots sits at around 26c the middle at 24c and the top of the pot 22c, this is more optimal

Edited December 16, 2023 by Military Grade