VPD

[Bear777]

VPD, vapour pressure deficit as I just learned what that stands for. I did a little Google search and come across some recommended optimal VPD for veg and flower...so a couple questions come to mind, what tools are most using to measure it, and do I understand correctly that you need to be able to adjust the temperature to be able to dial in the VPD?

 

[Bullfrog]

In practice Ive found its pretty hard to maintain the perfect VPD. unless you have the perfectly insulated grow area humidifiers dehumidifiers climate control and all the blah blah.
Honestly I think you just do the best you can and try to keep the temp and humidity within a range. weed can handle shit going out of range here and there it aint the end of the world. Ive had nasty heat waves for over a week and i just get all the fans out and open the tent drop the EC right down and just ride it out. unless you want to run climate control equipment its mainly airflow and how you set up your tent that will control it

 

[Bear777]

In practice Ive found its pretty hard to maintain the perfect VPD. unless you have the perfectly insulated grow area humidifiers dehumidifiers climate control and all the blah blah.
Honestly I think you just do the best you can and try to keep the temp and humidity within a range. weed can handle shit going out of range here and there it aint the end of the world. Ive had nasty heat waves for over a week and i just get all the fans out and open the tent drop the EC right down and just ride it out. unless you want to run climate control equipment its mainly airflow and how you set up your tent that will control it

How would you drop the EC right down?

 

[OZIOZIAUTO]

Add water , maintain pH

 

[Bullfrog]

How would you drop the EC right down?

hydroponics you have complete control over the EC all the time. even growing in coco which is what i do you can add more water like OZI just said a drop the concentration of nutrients. lower EC makes the water more easy for the plant to drink which is crucial at high temperatures because the plant needs to transpire a lot more to keep itself cool

 

[OZIOZIAUTO]

Just be careful

What EC u at ?

What u crop ?

Tell me a bit more about your grow bro !

 

[OZIOZIAUTO]

hydroponics you have complete control over the EC all the time. even growing in coco which is what i do you can add more water like OZI just said a drop the concentration of nutrients. lower EC makes the water more easy for the plant to drink which is crucial at high temperatures because the plant needs to transpire a lot more to keep itself cool

Yea spot on

 

[OZIOZIAUTO]

Good advice in layman's terms aye

 

[Bullfrog]

Good advice in layman's terms aye

 

[OZIOZIAUTO]

Fuck yes BF
U on to it
Ya get big thick buds in coco aye , my last one was an auto in 7 ltr tub under 350 watts and I got half pound of buds , in soil this time no chemicals , sumfn different aye

 

[OZIOZIAUTO]

My

hydroponics you have complete control over the EC all the time. even growing in coco which is what i do you can add more water like OZI just said a drop the concentration of nutrients. lower EC makes the water more easy for the plant to drink which is crucial at high temperatures because the plant needs to transpire a lot more to keep itself cool

My EC was over 2 at one stage and I freaked out and backed off a bit , it was thirsty, NL#4 AUTO

 

[Bullfrog]

Fuck yes BF
U on to it
Ya get big thick buds in coco aye , my last one was an auto in 7 ltr tub under 350 watts and I got half pound of buds , in soil this time no chemicals , sumfn different aye

im a big fan of coco. but whatever floats ya boat is good

 

[Bear777]

Just be careful

What EC u at ?

What u crop ?

Tell me a bit more about your grow bro !

Oh I asked about how to drop EC, because Bullfrog mentioned above that is part of how they coped with a nasty heat wave for a week, so I was curious as how that would be done, thanks for both your inputs. I am doing soil, organic, just starting out on my indoor journey, and picking the brains of those here on this forum is going to help me do much better than if I hadn't found TSE.

 

[OZIOZIAUTO]

Good to hearing

 

[Love to grow]

Oh I asked about how to drop EC, because Bullfrog mentioned above that is part of how they coped with a nasty heat wave for a week, so I was curious as how that would be done, thanks for both your inputs. I am doing soil, organic, just starting out on my indoor journey, and picking the brains of those here on this forum is going to help me do much better than if I hadn't found TSE.

Growing in soil organic is very hard to pull off on your first indoor it’s all about the wet and dry cycles depending on your position on hydro nutrients I’d run coco for a first grow it’s just way more forgiving of overwatering than soil which is a newer growers biggest mistake normally anyways good luck with it mate get growing you won’t regret it becomes more addictive than the smoke

 

[VinDeezle]

Growing in soil organic is very hard to pull off on your first indoor it’s all about the wet and dry cycles depending on your position on hydro nutrients I’d run coco for a first grow it’s just way more forgiving of overwatering than soil which is a newer growers biggest mistake normally anyways good luck with it mate get growing you won’t regret it becomes more addictive than the smoke

I find I get far better results watering daily in soilless medium that has organic amendments. For ages I was trying to figure out why id always get burn starting in flower when water consumption increases. I find keeping it moist but not saturated leads to the best rhizosphere in an organically amended mix tbh.

Turns out it was pH/ec swing as the medium dried out. I water from the top in the morning (about 1-1.5L) and bottom feed a bit later on in the day (whatever it will suck up) at the moment and I find I'm getting far better results than when I had a wet/dry cycle which I didn't expect.

Itchy actually clued me on to the top burn from under watering in an amended mix. All these have been watered daily, if not twice a day from about week two in a peat/compost and organically amended mix.

One thing I've noticed lately is that 90% of the "overwatering" issues have actually been underwatering. Most peat, Coco and compost mixes hold over 20% air when saturated, and if properly aerated daily watering shouldn't be an issue contrary to most opinions.

 

[Love to grow]

I find I get far better results watering daily in soilless medium that has organic amendments. For ages I was trying to figure out why id always get burn starting in flower when water consumption increases. I find keeping it moist but not saturated leads to the best rhizosphere in an organically amended mix tbh.

Turns out it was pH/ec swing as the medium dried out. I water from the top in the morning (about 1-1.5L) and bottom feed a bit later on in the day (whatever it will suck up) at the moment and I find I'm getting far better results than when I had a wet/dry cycle which I didn't expect.

Itchy actually clued me on to the top burn from under watering in an amended mix. All these have been watered daily, if not twice a day from about week two in a peat/compost and organically amended mix.
View attachment 39271
One thing I've noticed lately is that 90% of the "overwatering" issues have actually been underwatering. Most peat, Coco and compost mixes hold over 20% air when saturated, and if properly aerated daily watering shouldn't be an issue contrary to most opinions.

Oh yea different strokes for different folks for sure mate and you have whatever your doin down pat I’m just sayin for a newer indoor grower soil may not be the best option as like u said all through the grow cycles your needs for water change in soil where as coco once the root system fills out the pot you can smash em with water with no worries

 

[Bullfrog]

I find I get far better results watering daily in soilless medium that has organic amendments. For ages I was trying to figure out why id always get burn starting in flower when water consumption increases. I find keeping it moist but not saturated leads to the best rhizosphere in an organically amended mix tbh.

Turns out it was pH/ec swing as the medium dried out. I water from the top in the morning (about 1-1.5L) and bottom feed a bit later on in the day (whatever it will suck up) at the moment and I find I'm getting far better results than when I had a wet/dry cycle which I didn't expect.

Itchy actually clued me on to the top burn from under watering in an amended mix. All these have been watered daily, if not twice a day from about week two in a peat/compost and organically amended mix.
View attachment 39271
One thing I've noticed lately is that 90% of the "overwatering" issues have actually been underwatering. Most peat, Coco and compost mixes hold over 20% air when saturated, and if properly aerated daily watering shouldn't be an issue contrary to most opinions.

I water up to 5 times a day in summer with coco. basically depends on the size of the pot but smaller pots ill add a watering cycle everytime i lose 5-10% of the pots total volume in water.

 

[VinDeezle]

Oh yea different strokes for different folks for sure mate and you have whatever your doin down pat I’m just sayin for a newer indoor grower soil may not be the best option as like u said all through the grow cycles your needs for water change in soil where as coco once the root system fills out the pot you can smash em with water with no worries

i feel ya. I certainly struggled for a while when switching from coco to an amended potting mix. The first few looked like deaths dick by the time I was done lol.

 

[VinDeezle]

on the topic though, I've never chased VPD as there has been times where my VPD has been so out of whack (3's and up) and the plants always looked fine at that stage, so I just took it with a grain of salt. My closet is generally dry as the lights heat up the closet over time and there is inadequate exhaust out the room. Couple that with small plants and humidity is low. It's usually 30% and 35c in summer and the plants are always upright. If I run a humidifier and decrease the temps 3-4c to get to an adequate VPD I end up with droopy plants and mold if late in flower like clockwork.

To put it simply, due to my hot environment once summer comes, sticking to VPD just creates a humid sauna for some reason and my strains just don't deal with it. I'll let it go up 5c and drop 40% humidity and they are immediately happy. Unless you have good temp control it can be a bit of a pain to chase.