Inkbird Environment Control Automation - VPD Made Easy!

[zen-ken]

1 hour ago, mikeydoughnut said:

@NezA sounds like your journey is planned out. Wish i could be so organised. Good luck with the living soil n that. I like how its pretty much how nature intended but theres no way im having worms in my house!  

 

@superfruit this is what i learned, again, practically the other day. Cannabis can can consume ridiculous amounts of light energy. I believe its the far red spectrums in HPS that will generate the heat (uv). Have you got a fan speed controller? Try and use that to negate the heat generated by the hps. A cannabis plant can efficiently use upto 2000ppfd. This is assuming you are feeding enough and watering is bob on. You want to use as much light as possible whist controlling temps. So a combination of extraction and oscillation of air over the leaf surface could bring your temps and humidity down in one swing of the bat. The crucial thing here is leaf surface temp. I hear its around 1/2 degrees below ambient air temp, i could be wrong. Depending on you stage of growth it might not take much tweaking. If you're about to go into or in flower get those numbers down as best you can. 

 

I was watching a video on youtube and a lady said she understands the frigtening thought on budrot but if you follow the vpd and its in balance you should be good .... obviously 70/80% humidity isnt good but a bit above or below ideal isnt the end of the world.

 

Apologies if i mistook what you were discussing, my heads fried from home schooling.

2000ppfd is the absolute limit and that's with CO2.....the ppfd provides a very diminishing return as you take it over a 1000.

VPD is great in the first weeks....after week 4 of flower I would completely ignore it or ur rock hard buds will get bud rot ime.

 

Watch the Bruce Bugby video and you will see what I mean.

[zen-ken]

2 minutes ago, superfruit said:

 

Edited January 21, 2021 by zen-ken
Didn't read the post properly

[Shumroom]

Remember when looking at temperatures,

try to stick to either C or F,

don!t mix the two 

 

 

So +5F is really nearer +2 or 3 in C,

but it's not a linear scale so best to convert to the same scale.

 

Atb

 

 

[mikeydoughnut]

@zen-ken totally agree and respect your knowledge as it’s far greater than mine. 

 

In my own head thought perhaps rather than looking to change lights etc I’d first look to bring temps down by other means. Having said this I dunno what size hps he/she has and how much ppfd is being provided. 

 

However i do bow down to greater knowledge. I know me place  

[mikeydoughnut]

To be fair sounds like you’re all over it @superfruit. This vpd does make things complicated and dunno about you but I’ve found myself worrying about stuff I’d never thought of. I’m still at a learning stage. I think there’s such thing as too much technical knowledge without the practical skills to implement it. I think I’ve gotten to that point now. I’m going to put the vpd book down for a bit and just use the basic principles and as @zen-ken said in the second half of flowering just use me own loaf.

 

cheers bud I appreciate that. Educated children only benefit society. Happy to do my bit.

[zen-ken]

Just now, mikeydoughnut said:

@zen-ken totally agree and respect your knowledge as it’s far greater than mine. 

 

In my own head thought perhaps rather than looking to change lights etc I’d first look to bring temps down by other means. Having said this I dunno what size hps he/she has and how much ppfd is being provided. 

 

However i do bow down to greater knowledge. I know me place  

I wouldn't say that Mikey.....your skills are easily catching up to mine.....I've just got more experience of mistakes is all....always feel free to question anything I say...u know I love a good discussion to get to the facts brother.

I'm no Bruce Bugby

 

 

[zen-ken]

Its only cause the suggested VPD at 60 RH is gonna cause mould.

Its right for growth.....just not good for rock solid bud 

[mikeydoughnut]

 I was lay in bed with Bruce the other day taking notes. I felt dirty 

 

That’s the thing we’re all here to learn and one of the best ways to learn is realising when others are right. See a lot of back and forth on here, even with established growers who can grow with their eyes closed.

[zen-ken]

Just now, mikeydoughnut said:

 I was lay in bed with Bruce the other day taking notes. I felt dirty 

 

That’s the thing we’re all here to learn and one of the best ways to learn is realising when others are right. See a lot of back and forth on here, even with established growers who can grow with their eyes closed.

I'd love to give Bruce's  method a crack....seems so simple.....peat, vermiculite, gypsum,dolomite lime etc.

No ph and just an EC meter.

Feed at 1.3 - 1.4 till the run off reads the same....massively difficult to over water....heaven.

 

I'm really struggling to import the blue powder tho....I looked into it and it was as much to ship as to buy....I was also worried it may be a banned fertiliser ie bomb making gear.....I'd be ruined if it got stopped at customs and they came to see that im a personal grower and not a terror bomber.

[NezA]

I followed the VPD chart all the way to harvest and this Disco Biscuit has some pretty solid buds absolutely no rot whatsoever. But this is my first run following the chart perhaps I was lucky. We'll see if it was a fluke or not as time goes on. I'm planning to continue following the charts from here on out so time will tell.

 

I've never had rot before so if I get even 1 instance that'll be a deal breaker for me and I'll switch to the method suggested by @zen-ken but so far so good.

 

I think it's the balance of humidity and temp that's the key as to why a lot of people don't encounter rot when following VPD. If you had say 60% humidity and 22c temps then there's not enough pressure on the plant to transpire causing the air around the plant to become stagnant. My theory is if stomata are kept constantly open and constantly exchanging gases then the air can't stagnate and the microclimate around leaves and buds is constantly changing through the plants own metabolic processes. Just a hunch based on my own experience and the learning that I've done over the last year or so.

[superfruit]

16 minutes ago, zen-ken said:

I've just got more experience of mistakes is all

 

Yeah this exactly, I've always thought the best way to learn something is to learn from a combination of others and your own mistakes. Some good advice I was given when becoming a new parent, was to accept the advice from others, account for it in your own decision making and then learn from whatever decision you ultimately come up with. Don't just copy-cat - there are too many variables.

 

For me, using a hps makes sticking to the Pulse charts a little difficult due to the difference in leaf temps, and copying @NezA Inkbird settings would be incorrect, so instead I'm going to:

• let the HPS and Inkbird (oil rad) drive a lower temperature of around 22-23-24c (undecided) which should give me a leaf temp a few C higher.
• let the Inkbird during veg keep RH up nice and high around 63%, dropping it during flower.
• RootIt heat matt/thermostat will keep roots to 24c through the entire grow.

My last (and first) grow produced some nice smoke and a good yield, but I was definitely cooking the plant with my temps. I was figuring my 400w HPS was doing a great job keeping everything at around 25-26c but now I've read up about LST (not the training - leaf surface temperature) I realise they would have been anywhere from 30c to 34c at times, explaining why some looked a bit on the burnt side and produced some airy buds in places.

 

I went straight to finals (auto), 24/0 lighting too. This time I'm switching things around as per the above bullet points, 20/4 lighting and will be potting up to final (once).

 

Whatever the outcome is, will be knowledge gained for the next grow. 

 

p.s. if if none of this work, probably end up buying some DIYLED gear and sticking to the charts  

Edited January 21, 2021 by superfruit
ps

[NezA]

Aye @superfruit the settings aren't necessarily there to be copied per se just a guide about how to create them. As I explained in the early posts this was based on an assumed leaf temp offset.

 

It's important people take the time to understand the relationship between all the different readings as any variance between my grow space and yours will impact what settings you need to apply for optimal VPD

[superfruit]

Just now, NezA said:

Aye @superfruit the settings aren't necessarily there to be copied per se just a guide about how to create them. As I explained in the early posts this was based on an assumed leaf temp offset.

 

It's important people take the time to understand the relationship between all the different readings as any variance between my grow space and yours will impact what settings you need to apply for optimal VPD

 

For sure! It's amazing how much those charts can change by even 1C leaf temp offset. It's definitely a science and realistically device accuracy alone is going to throw most of us off-track a little. Our cheap inkbirds vs laboratory grade equipment n all haha

Edited January 21, 2021 by superfruit

[zen-ken]

26 minutes ago, NezA said:

I followed the VPD chart all the way to harvest and this Disco Biscuit has some pretty solid buds absolutely no rot whatsoever. But this is my first run following the chart perhaps I was lucky. We'll see if it was a fluke or not as time goes on. I'm planning to continue following the charts from here on out so time will tell.

 

I've never had rot before so if I get even 1 instance that'll be a deal breaker for me and I'll switch to the method suggested by @zen-ken but so far so good.

 

I think it's the balance of humidity and temp that's the key as to why a lot of people don't encounter rot when following VPD. If you had say 60% humidity and 22c temps then there's not enough pressure on the plant to transpire causing the air around the plant to become stagnant. My theory is if stomata are kept constantly open and constantly exchanging gases then the air can't stagnate and the microclimate around leaves and buds is constantly changing through the plants own metabolic processes. Just a hunch based on my own experience and the learning that I've done over the last year or so.

I always aim to get it around 50 going to 40 for the very last weeks.....but you make some very compelling points brother.

I may need to invest in a better humidifier and give it a go.

Edited January 21, 2021 by zen-ken

[zen-ken]