New Grower My first Auto grow

[Lil Dab]

So it's finally under control no more condensation. However I now have 1 intake and 2 exhausts. Interestingly it was always just 1 side on the tent where condensation would form and that's the side opposite my furnace. So maybe that side has the coldest exposure??? B4 I read about VPD I just ran the fan on high and honestly didn't care that my RH was around 40. But because of reading about VPD I realized I really wanted a higher %RH.
Even at like 78F b4 it would form condensation pretty rapidly on the back wall.
The thin t shirt slowed the air exchange rate and the passive exhuast vent on the back wall above the intake seems to have helped. I even ran the air intake "duct" to the middle of the tent to keep the cooler air away from that back wall.
Currently with this set up my temps fluctuate from say 73 to 76 and the % RH from say 56 to 60.

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plants look great but am wondering if you can open up one of the vents on the bottom of tent rather then using the hose as intake... cause it doesn't look like there is a fan on there but maybe i am not see it or too stoned... here is my setup i use both the mesh vents and fan as intake but the fan isn't really necessary it helps when the exhaust can't keep up

 

[Kirka88]

plants look great but am wondering if you can open up one of the vents on the bottom of tent rather then using the hose as intake... cause it doesn't look like there is a fan on there but maybe i am not see it or too stoned... here is my setup i use both the mesh vents and fan as intake but the fan isn't really necessary it helps when the exhaust can't keep up
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I did previously try swapping out a 4" tube about 12 inches long in place of the black shop vac hose you see as the lower air intake. Unfortunately that seemed to exacerbate the problem with condensation building up even faster.
Now I could try it again with the current exhaust set up???
Really the shop vac hose was just an attempt to prevent light filtering in when I was running photos and need a 12 hour dark cycle lol.
In fact originally the intake and exhaust were both on the backside of the tent (to keep light out). At that point the condensation was moderate. I moved the exhaust fan to it's current position opposite the intake and the problem got worse!
It's a head scratcher! At the moment my best guess is I hit a sweet spot between RH and air exchange?
Maybe just maybe the fan is blowing more on that back wall thus causing evaporative cooling ? Which in turn amplifies as more condensation builds up????

 

[Lil Dab]

I did previously try swapping out a 4" tube about 12 inches long in place of the black shop vac hose you see as the lower air intake. Unfortunately that seemed to exacerbate the problem with condensation building up even faster.
Now I could try it again with the current exhaust set up???
Really the shop vac hose was just an attempt to prevent light filtering in when I was running photos and need a 22 hour dark cycle lol.

Yup now we’re outta my realm that’s why I don’t do photos I don’t worry about light leaks I just go for good airflow and keep my lung room 70-75f <50%rh

 

[Kirka88]

Dec 17
Fertilized with MC 1 part strength 1 tsp/gal. (4 grams). Plants felt light and soil was barely moist. It took ~ 3/4 gal/plant to achieve minor but obvious runoff. They seem to be getting thirsty. Clear indication of starting to enter flower I feel. At this point I'm hoping they start stretching.
Lighting still 20/4. Had to raise them a bit out of concern for burning the leafs. 550 PPFD 75F 60% RH.
So far I'm pretty pleased with the ways things are going. Wide open to suggestions or advice!!

 

[DCLXVI]

Plants look like they are growing well. Do you have a circulator fan in your tent? Just something to blow the air around a bit. It will help a ton with keeping things stable and preventing condensation. I would suspect the condensation was from an area where the air stopped moving.

A cheap clip on desk fan from amazon can do in a pinch. Same with a couple computer case fans ziptied to the corner poles.

Oh, one other thing to consider when this run is finished. I see your tent is sitting on the concrete floor. That is an infinite heat sink. Run by HomeDepot or Lowes and pick up a piece of large foam insulation board. Find the cheapest one they have even if it's only 1/2" thick. Have them cut it in half for you and stick that under your tent. If your tent is a 4x4 then half a sheet fits perfect. You could put both pieces if you like. It will help keep things stable as the floor won't be constantly sucking the heat out and effecting the temp/humidity.

 

[Kirka88]

Great idea!!!
I do have a clip on fan going though it's not the oscillating type but it does keep the air moving. Your dead on it's basically sitting on the concrete floor I have a tarp under it folded to 4 layers but honestly that was only intended to protect the bottom of the tent not insulate it.

 

[Kirka88]

Dec 18
So approx 24 hours since fertilizing. I'm hoping I'm still in a good place with respect to nute burn. There is just a touch of discoloration/yellowing at the very tips of a few leaves. I'm hoping this is because they grew just a touch too close to my lights (16" vs my usual 18") ??
I'm considering trimming back a few of the lower branches not full on gung ho (lol) just moderate . There just starting to indicate flowering and this is when I would do it with photos......
600 PPFD, 73f, 65%RH

 

[Kirka88]

Lollipoped all plants bottom up went conservatively for concern of stressing them.
600 PPFD , 74F, 55% RH

 

[Delps8]

600 PPFD?

To me, 600 is low at day 36 but a lot of growers are putting on the brakes at that point even though cannabis can handle 800-1000µmols and, second, plant and crop yield and quality increase directly as light levels increase (usual caveats).

"discoloration/yellowing at the very tips of a few leaves. I'm hoping this is because they grew just a touch too close to my lights (16" vs my usual 18") ??"
Discolored leaf tips is a classic symptom of nutrient levels being too high. Excess light usually starts with "light avoidance" such as tacoing/canoeing or where the leaf rotates around the petiole to avoid light.

How are you measuring PPFD?

 

[Kirka88]

600 PPFD?

To me, 600 is low at day 36 but a lot of growers are putting on the brakes at that point even though cannabis can handle 800-1000µmols and, second, plant and crop yield and quality increase directly as light levels increase (usual caveats).

"discoloration/yellowing at the very tips of a few leaves. I'm hoping this is because they grew just a touch too close to my lights (16" vs my usual 18") ??"
Discolored leaf tips is a classic symptom of nutrient levels being too high. Excess light usually starts with "light avoidance" such as tacoing/canoeing or where the leaf rotates around the petiole to avoid light.

How are you measuring PPFD?

I'm using the PPFD meter app which is in truth not calibrated since I don't have the necessary instrument to do this.
That said 20 hours at 600 PPFD should put me around 43 mols for DLI
I was going by a couple of different lit references which I thought suggested 600 PPFD for veg. The 43 DLI should put me in the correct range I also thought?? At least for the veg state?
The yellowing does concern me for exactly the reason you stated. What I do oberve is some have it to a very minor extent yet others (all the same strain but different seeds) don't all watered with the same amount and concentration of MC part 1 fertilizer...
So one thought is since I just increased the concentration of the solution if it's being caused by my nutes levels being too high I should see an increase in the yellow tip effect???