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What Is Your Vpd....

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What Is Your Vpd....

hammerhead 45 Replies 13,568 Views
Page 1 of 3 · Replies 1–20 of 46
hammerhead

hammerhead

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#1
I have seen alot of people referring to these VPD charts lately.. I got curious what do you keep your room RH% at day/night... According to the VPD chart if your room id 82f you need 70%rh for a correct VPD. Does anyone keep the room at this high rh%.


I have been running my room at a stable 45%rh for lights off/on. I don't see any issues but according to the chart my VPD is way to low.
 
#2
I'm going to make a humidifier like one member posted.

Mine is constant at 78°~82° and humidity at 48%
This is au natural. Dehumidifier never kicks on. Was hoping I could use the waste water from the dehuie for my nutrient reservoir.
 
#3
1.0 kpa vpd night and day. Never lost a single nug to bud mold from 70+% RH

triangle kush x bubba just starting week 4 bloom

IMG 20150518 102424053
 
#4
@midwestdensies @Capulator @Texas Kid @DonJuanMatus i know there are a few others rocking high temp/humidity. I may have tagged a few of the wrong people but I know some are on that Miley bangers tour rocking the vpd to its fullest.
 
#6
From what I have read the correct VPD improves yield.. I wont be able to control a 70%rh environment with any precision. I would be more concerned with PM then bud rot. I don't use co2, I don't run high temps. I will keep reading and asking for info. Never to old to learn new stuff.
 
#8
hammerhead said:
From what I have read the correct VPD improves yield.. I wont be able to control a 70%rh environment with any precision. I would be more concerned with PM then bud rot. I don't use co2, I don't run high temps. I will keep reading and asking for info. Never to old to learn new stuff.
Click to expand...

My last run hit 2# per light, no scrap ,with only 7 foot ceiling on the tent and 4-4 1/2 foot bushes. Only running 4 1k hps in a 10x10x7 tent. 16 girls

If you're not running co2 then you absolutely don't run high temps. I'd say 76 without co2 which means lower rh . if temps go down so does rh and vice versa if temps go up so does rh
 
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#9
I use this calculator instead of the graph..much more precise



Works on my phone so I always have it on hand
 
#10
God damn six strang you need dogger or two in that bitch lol. But from your threads I can tell it's not a necessity! But I could only imagine you in an environment 84f, 80 rh, and 1200 ppm lol @sixstring is a prime example of giving no fucks when it comes to vpd
 
#11
Damn can't believe I left @Billyboat & @Confuten1 out, I love y'all's threadss
 
#13
I'm pretty sure @midwestdensies said he dials it back around week 6 too. He hasn't chimed in yet because of the strippers and don p, but that's a different thread... Lol
 
#14
Texas Kid said:
I am almost dead on the optimal based on that chart but I do have to dip it way down from week 5 or 6 in flower under the DE lights because the colas are so big you run the risk of bud rot in the core of the giants
Click to expand...

This is exactly what I'm terrified of. Ran green crack last run, everything was chunky and had many colas the size of my arm. Cracked one open, boom bud rot in the center :9

That being said, the science behind running higher rh with optimal vpd seems solid.
 
#17
I run 70-75% RH first 5-6 weeks... 82 degrees. 8- 900 ppm CO2. After that I drop my RH to 60 and at week 7 to 50. I pull the rot prone strains early like starfighter and orange cookies because no matter how low the RH is those strains will get rot usually around day 60+.

When my little temp/RH meter shows the frowny face, I know I am in the sweet spot. LOL.

EDIT: forgot to mention the last week or two I drop temps to the 60's to encourage those nice colors. Almost all my strains go purp and orange. I love that.
 
#18
Anyone alter temps to achieve better vpd?

I'm waiting on my humidifier and lowering temps in the mean time. My rh at lights on maxes out at 60%, so have set the mini split ac to low 20's (°c)..

Peace
BL
 
#20
midwestdensies said:
80S 70-85rh 1100co2 per spurr. Week 6 dial down temps 78 50-60 rh. Ha ya man we like to party
Click to expand...

Spurr is the man. So thankful for that guys threads and posts that are still around. 10 months ago I was running 1500-1600 ppm co2 with no clue about vpd. Never even heard it before. Then I started googling best co2 level and came across his thread on IC . my last two grows and currently my third one I've been applying his knowledge and recommendations and straight killing it.
 
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