[mrgrowit]

Has the moisture content been consistent in the grow pots? If they dry out, microbes can go dormant and the organic matter breakdown will slow down or even stop. That can certainly result in the plant not being able to absorb the nutrients it needs. Those fabric pots do have benefits but with organics it can be challenging since they can dry out from all sides. The yellowing could be from either a lack of nutrition (my guess is your fresh soil has the nutrients, it just needs to stay moist), or often times the lower leaves that aren’t receiving light will die off.

[mrgrowit]

Hey thanks so much for your positive words! Do you have more info on your grow and some pics?

[mrgrowit]

Your question: “Would under watering affect the nutrient uptake toward the sides of the fabric pot that was always dried out?”
Answer: Dried out soil could absolutely negatively impact nutrient uptake. When the soil is dry, microbes go dormant. When they are dormant, they aren’t actively breaking down organic matter converting it into a form that the plant can uptake.

Your question: “Maybe the middle of the pot was depleted of nutrients from veg and the outer portion of the pot was to dry to contribute?”
Answer: Interesting thought but it’s pretty much impossible to say for sure the middle of the pot was depleted vs the outer sides of the pot.

Your question: “Replaced the old RO with a six stage mid grow. Possible issue?”
Answer: I agree with what @CamZ says in the post above me. To add to that, if you add minerals back into the RO with that 6th stage filter, you may need to adjust the ratio/dosage of the other fertilizer you add in. For example, the 6th stage filter you have says it adds back in calcium, magnesium, and potassium ions. Therefore, you should be cautious when adding in additional inputs that have those elements in them since too much of one element can inhibit the uptake of other elements. Keep in mind that this is general guidance and I’m sure many people have the 6th stage RO and ignore what I just mentioned and their plants turn out fine lol. So I guess it comes down to how much you want to gamble haha… You mentioned on 10/26 you were going to feed; what fertilizer did you use?

[mrgrowit]

Thanks for the support on Patreon! Which AC Infinity controller do you have? I ask because some of them allow you to set by VPD, so your fan could kick on according to that instead. Or, if humidity is too high, or temp too high. Lots of flexibility with that controller. Also the humidifier will connect to the newer controller; not sure if the older one can.

I’ve heard of the tube on the humidifier causing issues too. I personally don’t use it.

Your question: “How does brix in cannabis relate to terpenes and bud quality? … perhaps bursts of low vpd stress through until the mid-phase of flower could be beneficial?”
Answer: I’m not aware of any studies to back up that. All I hear is anecdotal evidence.

Are these the same plants being transplanted into 7-gallon grow pots soon or are those different plants? If they are being transplanted soon, the larger grow pot with fresh nutrients may be all it needs to bounce back.

[mrgrowit]

If the leaf surface temperature is optimal then most likely the soil temp is fine. Even though you’re bringing in 64°F air, you’ll be surprised by how the heat generated from the grow lights can keep the space warm.

[mrgrowit]

Beautiful picture with the cover crops! Yes you can try to rehydrate and calibrate the pH meter but there is a high likelihood that the probe is no longer good. Without the pH measurement, we don’t know if the medium is in the acceptable range for nutrient uptake. If the pH in the medium is too high or too low, you could get nutrient lockout and see deficiencies. Without the PPM measurement, we are also just guessing what the problem could be. It could be too low of PPM indicating it needs a feeding, or too high of PPM causing a nutrient lockout. So it’s really hard for me to suggest something for you at this point when we really haven’t figured out what is causing the problem. If I had to guess without pH or PPM measurements, I’d think it was a lack of nutrition in the medium since all plants are impacted and all are yellowing all over. I wish I could give you a better answer.

[mrgrowit]

Well the plants look to be yellowing all over which makes me rule out light burn. The Sohum soil should get you through the entire grow without any additional feedings. How long did you Veg for? Maybe a long veg period and now in flower they are out of nutrients? Are you able to get a pH or EC/PPM measurement? I know it’s not routine to do those measurements when growing with organic inputs but that info can be helpful if there are problems.

Light distance, temp, and RH look fine. You mention no water in over a week; Are you keeping the medium moist at all times or doing drybacks between waterings?

[mrgrowit]

I highly recommend the AC Infinity humidifier (discount code: MRGROWIT15) over the Levoit smart humidifier. Not only is the AC Infinity humidifier priced lower, but it is able to dial in RH way better than the Levoit one can. I actually stopped using the Levoit humidifier.

Which inline fan are you using right now? Does it have a variable speed controller? Also, is it on a timer? Hard to tell you for sure if the humidifier will sufficiently increase the RH if you’re constantly exhausting air from the grow space.

That damage on the lower leaf resembles beginning symptoms of over-watering imo. Basically it’s a lack of oxygen in the root zone and the leaves on the lower part of the plant suffer first. Again, are you tell you for sure that’s what it is, but it sure resembles it. Letting the soil dry out a bit more between waterings should eliminate that from getting worse.

In regards to what you mention about easier to control RH in flower, it can be. The bigger the plant the more water vaper will enter into the air via respiration.

[mrgrowit]

Looking good! Nice job

[mrgrowit]

Yes 2-4 days you may see burnt tips or leaves become much darker and/or shiny if it ends up being a problem.

[mrgrowit]

Hey @jd187 those are both male plants – not hermaphrodites. All generations are regular seeds so they can be either male or female. Are the other 2 you mentioned you have confirmed females?

[mrgrowit]

Can you include pics so I can see what you see? Are they F1, F2, or F3?

[mrgrowit]

Yup 1 tsp matches the dosage it mentions on the back of the bottle for the stage/size of your plants (assuming they are the same plants from your other post). Here’s what it says:

Roots Organic CalMag
“Seedlings and small plants
Use 1 teaspoon (5ml) per gallon
Mature vegetative plants
Use 1-3 teaspoons (5-15ml) per gallon
Mature flowering plants
Use 2-3 teaspoons (5-15ml) per gallon”

Many growers will give CalMag every watering while they give their regular fertilizer every-other watering. However, there are many ways to go about it. How do you plan to use the fertilizer? Yes adding nutrients then pH after. In soil, many strive for 6.5 pH while the general range is 6.0-7.0pH. Some growers go outside that range and their plants turn out fine though. So this is something you really don’t have to be 100% precise on IMO.

I believe I touched upon all of your questions but let me know if I missed anything.

[mrgrowit]

I agree with @CamZ … Also, do you see any signs of pests? The white spots on the leaves make me wonder if it’s pests doing that or just some of the xtreme gardening blend getting onto the leaves.

[mrgrowit]

The clawing you show in the first pic you posted on 10/14 is a sign of nitrogen toxicity. However, the color of the leaves isn’t too dark of green, they aren’t shiny, and the clawing is only on a few leaves. Some times the plant will “grow out of it” as long as you’re only giving plain water without any additional fertilizer. I wouldn’t worry unless in the following days it appears to be getting worse or you see the other symptoms I mention.

The temps, RH, and light distance you mention are fine. What you mention as “blistering” looks like normal growth.

Your question: “Can the metal probe burn leaves on extended contact?”
I don’t think the probe gets hot enough for that.

You’re doing a great job so far. Growth looks fantastic. Keep up the good work!

[Author]

Posts