NorthernCosmos' First Indoor Soil Auto Grow: 2019

Thanks NC! And a bug-free new year to you and all :).
 
It's Day 75 for the senior AK420 (amber on sugar leaves, chopping time soon), day 62 for the senior BCN (trichs getting cloudy), day 46 for the Amnesia and White Widow and day 23 for the junior AK420 and BCN.

I have one worry and that is the main cola of that super bushy AK420. As you can see it has yellowed and crumbling leaves in the cola and canoeing leaves near the bottom of it. The rest of the plant looks fine. It has started to drink less than it used to though, and the pot is still heavy, so I'm skipping this watering. Any ideas? Overwatering with symptoms only in the biggest cola/branch, or something else? I'm not sure what to do - chop it now'ish before leaves in other colas starts drying out?

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Apart from that one worry, things are going well. The new Amnesia (front left) and White Widow (rear middle) are positively strutting their stuff compared to the previous ones, with a nice height and radius. The difference is no root-aphids or fungus gnats, perlite added to soil (instead of crushed clay pebbles), a bit more nutes and of course a day/night cycle as opposed to the eternal daylight the others saw:

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Heat stress - that could be it - I did actually raise the light 4 inches or so with that possibility in the back of my head. The lights were hanging low from the finishing of the previous plants, and that is the cola that was closest (until the new Amnesia and Widow passed it in height). The temps have been around 27°C (81°F) at mid-plant height, and the RH at around 40% ever since I started this grow.

As you see in the tent picture, everything is nice and green (well, I snip off the odd yellowing leaf, but that's fine) - then that one cola stands out as yellowing.
 
It's possible it's overfeeding but I still think it's heat stress. Here's a snippet and pic from another website for something to reference it to.

Your cannabis plant can only withstand a certain amount of heat and light. After a certain point, your cannabis will start exhibiting signs of stress on the leaves near the sources of light and/or heat. Your leaves will get yellow or brown brown spotting and may appear generally burnt in places when there’s too much light. It’s also common for leaves to curl up or down, fold inward like canoes or tacos, and for the serrated edges of leaves to start flipping up.

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Those taco/canoe and curling leaves look exactly the same. Right, I'll have to do something to manage the heat in that tent, because I want to be able to keep the lights close. Moving LED drivers outside and/or getting a stronger fan are possibilities. For now I'll open another top vent and see if convection cooling does it.
 
NorthernCosmos said:
Right, I'll have to do something to manage the heat in that tent, because I want to be able to keep the lights close.
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Just keep in mind that you may cause the plant to foxtail if the lights get too close. If the light gets too close for too long it causes a rapid growth of the calyxes.

 
I've gone through the exhaust filter/fan system, and it turns out there's next to zero flow, so there's as good as zero cooling effect at all from the extractor. No wonder I get better cooling from opening the top vents and let convection do the job. "Top Quality" (as claimed by the seller), my nether regions... Bit of a bummer, that.

I made a thread about it here, if anyone has any experience with this kit or any tips for making it better, please chime in.
 
Just jumping in to mention that heat stress and light stress can happen independently of each other.
 
^^ Correct, but the mention he was going to lower the lights tells me he probably shouldn't since the plant is already showing it's sensitive to environmental changes, in this case high heat. I'm a believer in if it's working don't mess with it. The plant is already stressed from heat... no sense in bringing the lights down lower right now imo. Let them finish off over the next couple of weeks at a safe height.
 
The humidity here is low to begin with; in the winter the air is bone dry, and I'm lucky to get 30% RH. Therefore I run an atomizing humidifier to get 40% in the tent. Even that is a tad low, if I'm not mistaken, but I have to keep tent parameters that support seedlings, veg and flower at the same time.

I seriously suspect that the filter is crap. For it to let The 250m3/hr through, it would require a J-79 on full throttle or something like that :p :

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Dupe post...carry on!
 
MrSauga said:
All I can really comment on is humidity plugs those carbon filters up pretty quick. @Virgin ground tried replacing the charcoal I think or may have ended up with a different unit, but many struggle with airflow once humidity gets in the blocks the filter
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It's a total pain in the butt and super messy to try to recharge or refill these filters.I can get an iPower for less than $50. The mesh on these filters is easily bent out of place and there are a bunch of rivets to contend with. Then you have to pack tightly and aside from that the charcoal isn't exactly cheap either. You need a considerable amount. For me the cost savings wasn't enough to warrant me messing around with it.
Some of the new filters have a removable/ replaceable cartridge. They are super spendy though.
@NorthernCosmos ... I answered on your filter help thread. Not sure if I'm helpful to you or not but I left my thoughts on the matter there.
 
MrSauga said:
Correct, but the mention he was going to lower the lights tells me he probably shouldn't since the plant is already showing it's sensitive to environmental changes, in this case high heat.
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Don't worry folks, that light is not getting any closer to the canopy! I'm sticking with the 4" increased height from yesterday, or even higher if that's what it takes. The reality of the matter is that I have ventilation/heat problems and need to find my footing here... I'll try running the extractor without the filter just to get a feeling for how much the circulation will affect the temps.

As mentioned in my ventilation diagnostic thread, I managed to double the flow by bashing the filter canister around, and TurboBucket suggested a little air compressor treatment which I will try too.

Next addition to the setup: new and less restrictive filter - but which one?
 
Update: I raised the light even more. It's now 17" above the new flowering plants, 20" above the "burnt" cola and 25" above the newest plants. I'm now down another degree C :) There is a lot of downwards radiated heat from the light.

BTW, part of the reason for going with the triple overlapping grow is that the distance from the light to the top of the plant is more or less self-adjusting as the plant grows (small autos) - I don't think it's too far off the generally recommended distances of 24" to 12". I've already also used the method of putting something underneath the pots to get an appropriate distance for each plant.

Anyhow, a little bashing of the filter, raising the light by maybe 6" in total and opening two of the top vents for convection resulted in a 2°C (3.5°F) temp drop, from ca. 27.5°C to 25.5°C (81.5 to 78°F). That's much better, but it's a makeshift solution just to secure the current flowering plants.
 
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