HOW TO WATER COCO FOR BEST RESULTS.

[3 balls]

There absolutely should be... the problem is that we still don't know the maximum ppm of co2 or ppfd at which benefits are the highest in order to really do this. I have a lot of trouble finding studies that go beyond 1500ppfd or over 800ppm co2. Personally I max my co2 out about 1200ppm and haven't seen any benefit beyond that. Bit thats not to say there isn't. Just I cant see it visually it if there is.

I would say with its between 5-10% lower RH depending on light and co2. Its also a balancing act if nutrient uptake and temp. So many moving parts, even the genetics. I grow hybrids and depending on whether they lean more indica or sativa also makes a difference. This is why VPD is a guide and not a hard rule and I would say understanding the concept and the moving parts involved is much more beneficial than just going by the numbers. I can say my experience is the more light you provide the more crucial the VPD becomes.

Its really good as a tool but not an absolute.

Maybe @Homesteader or @glo or another one of the science types could chime in.
I've run 1250ppm for many years, the only time I had any concern about RH is if it was too high. About a year, year and a half ago after not being able to turn around without hearing about VPD being the holy grail of environmental factors, I spent thousands on commercial hard plumbed humidifiers, their controllers and remote hygrometers hanging all over the place reporting back to headquarters. My honest results of it all are butt loads of dehumidifiers working overtime during lights out and the inability to grow any strain remotely sensitive to PM.
I'm not saying VPD is hogwash but I sure would like to understand in dumb guy terms how it relates to CO2.

 

[3 balls]

Apologies. I just realized I sidetracked the shit out of this thread. Maybe you guys could move it.

 

[Aqua Man]

Maybe @Homesteader or @glo or another one of the science types could chime in.
I've run 1250ppm for many years, the only time I had any concern about RH is if it was too high. About a year, year and a half ago after not being able to turn around without hearing about VPD being the holy grail of environmental factors, I spent thousands on commercial hard plumbed humidifiers, their controllers and remote hygrometers hanging all over the place reporting back to headquarters. My honest results of it all are butt loads of dehumidifiers working overtime during lights out and the inability to grow any strain remotely sensitive to PM.
I'm not saying VPD is hogwash but I sure would like to understand in dumb guy terms how it relates to CO2.

So 1 thing that may help is to keep the temp higher using heaters after lights out since humidity is relative. But also I think its been poorly communicated over the community about the need to run lower humidity and higher temps and what those values may be when running co2. Its common to hear that when speaking about co2 in general but then we hear VPD improves the uptake of co2 by controlling stomatal openings... but almost 99% of this information is for atmospheric co2 levels and that throws ppl for a loop.

I will always say with anything we should go by plants and while a lot of the information out there is very accurate if we change 1 variable then we need to consider how that will impact all other variables... and with VPD its not been done very well and thats why I think its more important to learn the concepts and put those into use and only use VPD as a guide.

 

[Aqua Man]

Apologies. I just realized I sidetracked the shit out of this thread. Maybe you guys could move it.

No worries... its related to VPD so I wouldn't call it sidetracked.

 

[Mr.GreenthumbOG]

You guys run crazy high ppm through your plants. I rarely go above 800. Ever!!!
Give the plants what they will consume. Nothing more. Why waste money on nutrients?
Watch the plants. Too much food, too many problems. Obesity!!!
the smoke is so much better if you don’t overfeed.
Mr.G

 

[3 balls]

You guys run crazy high ppm through your plants. I rarely go above 800. Ever!!!
Give the plants what they will consume. Nothing more. Why waste money on nutrients?
Watch the plants. Too much food, too many problems. Obesity!!!
the smoke is so much better if you don’t overfeed.
Mr.G

I think you could be confusing discussions of ppm as it relates to atmospheric CO2 with nutrient ppm.

 

[Mr.GreenthumbOG]

Atmospheric Co2 or not. I run co2. Waste of nutrients regardless.

 

[Aqua Man]

Atmospheric Co2 or not. I run co2. Waste of nutrients regardless.

We are talking about co2 ppm Not nutrient ppm

 

[Mr.GreenthumbOG]

Ahh. Gotcha. Read back.

 

[Aqua Man]

@3 balls if you keep temp differential at 2-5f your equipment for humidification and dehumidification will run much less and it should not impact node spacing. The higher the diff the bigger swing it creates and the more work the both have to do when the lights go off and come on... just thinking outlook as to what may help cut some wear and tear and running costs.

 

[Aqua Man]

Maybe @Homesteader or @glo or another one of the science types could chime in.
I've run 1250ppm for many years, the only time I had any concern about RH is if it was too high. About a year, year and a half ago after not being able to turn around without hearing about VPD being the holy grail of environmental factors, I spent thousands on commercial hard plumbed humidifiers, their controllers and remote hygrometers hanging all over the place reporting back to headquarters. My honest results of it all are butt loads of dehumidifiers working overtime during lights out and the inability to grow any strain remotely sensitive to PM.
I'm not saying VPD is hogwash but I sure would like to understand in dumb guy terms how it relates to CO2.

Oh and I 100% am with you on the only really a concern when RH is to high when using co2. Too low doesnt seem to be an issues that I have run into with co2 and I run a humidifier only about 2 weeks or so in the beggining. When plants are seedling and my co2 is set to 600ppm. After that they do the humidification for ne

 

[amekins]

I think you could be confusing discussions of ppm as it relates to atmospheric CO2 with nutrient ppm.

No there are definitely folks in this thread talking about 1200 ppm feeds. It baffles me but I’m also not attempting to push plants that hard.

 

[3 balls]

@Aqua Man I'm actually within that range. 74-79f. With a so called "sweet spot" for VPD of 60%RH @ 79f, it's a job getting down around 45% RH at lights out. I don't worry so much about the operating costs of it all, it's more that I really don't see me benefiting from the VPD effort and suspect it has something to do with my CO2 enrichment and the potential diminished return of VPD as they relate to each other.

 

[Aqua Man]

No there are definitely folks in this thread talking about 1200 ppm feeds. It baffles me but I’m also not attempting to push plants that hard.

Yup I can see it though. If running high co2 mod/high light and a higher humidity.

 

[Aqua Man]

I'm actually within that range. 74-79f. With a so called "sweet spot" for VPD of 60%RH @ 79f, it's a job getting down around 45% RH at lights out. I don't worry so much about the operating costs of it all, it's more that I really don't see me benefiting from the VPD effort and suspect it has something to do with my CO2 enrichment and the potential diminished return of VPD as they relate to each other.

100% you can't go by the VPD as it sits and thats because of the co2. You can make some changes but its probably just better to run a lower RH if possible

 

[Aqua Man]

Depending on strain im finding about 80-83f and 55% ish RH to work very well once they get a couple weeks into veg right until harvest.

 

[MIMedGrower]

100% you can't go by the VPD as it sits and thats because of the co2. You can make some changes but its probably just better to run a lower RH if possible

ok i’ll bite. Why does co2 make a difference for vpd?

 

[Aqua Man]

ok i’ll bite. Why does co2 make a difference for vpd?

Because it slows transpiratiin rates... VPD is designed to regulate transpiration for optimal growth and co2 uptake but an increase in co2 will result in reduced transpiration so we need to run a lower humidity to make up for this.

 

[MIMedGrower]

Because it slows transpiratiin rates... VPD is designed to regulate transpiration for optimal growth and co2 uptake but an increase in co2 will result in reduced transpiration so we need to run a lower humidity to make up for this.

Ok, why would increasing co2 slow transpiration rates. Isnt the whole point of supplementing it to raise transpiration rates?

 

[Aqua Man]

Ok, why would increasing co2 slow transpiration rates. Isnt the whole point of supplementing it to raise transpiration rates?

Because the plant is photosynthesizing more efficiently so it does not need to. This is always you always hear to get full benefits out of co2 we need to run higher temls and low humidity and very often a slightly higher ppm.