The following is a recollection of my first r indoor organic production run. For those kind enough to share, thank you for your insight. The setup: 3 gallon mesh pots FFOF soil P6 Platinum LED light Germinated 4 seeds from exotic genetix – Strain was called “Shrieker” which is said to be 80/20 Sativa. 5x5 Grow tent with inline fans creating air flow. The story: The 4 seedlings were introduced to the grow tent on March 1st. The grow light, which has a Veg and a Bloom switch, was turned to VEG only per the manufacturer. I was running something like 17/7 light to dark. Things seemed good for the first month or so, but then somewhere around mid April the smallest of the 4 plants (the runt) started to suddenly and quickly yellow. After some researching, I hesitantly came to the conclusion that it was a PH issue, as I was watering with tap water that registered somewhere between 7 and 8 on my PH meter. From the research I had done to this point, the one thing that stuck out was a sort of “less is more” idea – meaning keep the interventions to a minimum and don’t simply load up with a bunch of nutrients (lock up is worst than depletion). Therefore I assumed, rather than not enough nutrients, my plant was simply struggling to absorb the nutrients that were already in the soil and thus my conclusion of PH being the issue. To remedy I ordered some PH down from GH. At first I used this on the runt only. To my shocking surprise her yellow leaves turned back to green almost as quickly as they turned to yellow. With such great results on the runt, I began using it for all 4 of my ladies and none of them seemed to mind but I did notice one fairly odd thing. The leaves on the runt turned to a noticeably darker shade of green. The other 3 were more of light/lime green while the runt was more of a deep green. On about May 1st I decided to put them into flower by cutting the light cycle back to something like 11 hours. I also turned the “bloom” switch on in conjunction with the VEG switch. I did experiment a bit with the bloom switch just before I put them into flower, as the manufacture said BLOOM could be used for late stage VEG in addition to the flower stage. The ladies did not seem to like the BLOOM switch so I turned it back off until they started the flower stage. Even after entering flower they still didn’t seem to like the Bloom too much, but after several days it seemed like they acclimated to it. About a week into flower I noticed shiny silver like spots covering most leaves. I quickly concluded this was due to a pest infestation (maybe thrips) and treated with an OMRI listed insecticide foliar spray. In addition I also watered in some beneficial nematodes purchased from an online supplier. This worked, as all the signs pointing to insects issue went away. At around the same time, I noticed the biggest of the 4 plants was actually a male and so it was destroyed. Fast forward to week 5 of flower… as the end seemed close I thought I should stop adding the PH down so as to not taint the taste of the buds. I figured I should give them nice clean water, and thus began using Poland spring bottled water only. After a week of this the leaves really started looking unhealthy so I did my best to diagnose. All signs pointed toward light burn. I did zero training, so the main stems on each lady were approximately 10-14 inches higher than all the other off shoot branches. Each bud on each of the main stems showed the classic bleached white top – pretty much identical to the online pic s of bleached light burned buds. None of the other buds, in what one might call my canopy, are showing this bleaching but most leaves are showing classic leaf symptoms – frayed yellow then brown edges, but green center lines. Eventually even the green center turns brown and the leaf dies. As is also consistent with light burn, this was more pronounced on the top and on older leaves than on bottom or newer leaves. The main stem buds , at their closest point, were 14 inches below the LED. The manufacture recommends around 19 inches during the late flower stage so I raised my light to the ceiling putting it now 28 inches from the very tallest of my buds. NOTE: I feel like most of the buds were 19 inches from the LED even before I move the light. At this stage I did pick and smoke one bud as a test, since I have read light burn can totally deplete the bud of TCH. While only a very small sample, the test did indicate that the bud contained THC. I could not help but notice things went south after I stopped using PH down. To test this, I fed some to the runt but, unlike before, nothing seemed to change. I also, admittedly after the fact, tested the PH of the Poland spring water and it registered nearly the same as my tap water (7-8 range). Lastly, from a pic taken about 3 weeks into flower, an experienced grower did say my leaves were indicating a low level of phosphorus and potassium. At first I did not think this had much creditability because the pic was taken while the LED light was on so I feel it was greatly distorted. Either way, this piece of advice was at least something for me to go on so I pushed forward frantically trying to add these two nutes. I chose Kelp & alfalfa meal plus a bit of fresh human urine as my weapons of choice (I realize the meals take time to breakdown but did not want to add any other synthetics). I should also add that I did top dress a few times along the way with EWC and peat moss. This was done during both VEG and flower. At the moment: Since there’s still another week or two of potential flowering time left, I am in a sort of holding pattern. I can only hope the aforementioned interventions - especially raising the light – will allow the ladies to finish their life cycle on a somewhat strong note. What I am not sure of is whether or not I should start adding a bit of PH down to the watering again. I probably will since it seemed to help at one point and the PH meter is telling me the soil PH is basically matching that of the undaunted water (7-8). Conclusion: I feel like ultimately there was a combination of issues where a lack of nutrient uptake left the ladies far more susceptible to light burn. What I am struggling with is whether this is simply a PH issue – it’s too high for them to properly absorb the nutrients that are there -, or that using 3 gallon pots isn’t enough volume to support a full lifecycle unless the FFOF is heavily amended. Questions and Going Forward: Soil – The biggest change I plan on making will be the utilization of a super soil. I am highly attracted to the no till concept and really want continual use soil that, with my stewardship, only improves over time. Can this actually work with 3 gallon pots? I am sure there’s some minimal volume threshold but not sure if 3 gallons is above that or not? I recently came across a youtube clip where a guy named Minnesota Nice pulled back his straw top dressing and there was a worm! Real live worms in indoor containers - this is where I want to be. Also, should I bother adding the lime component if my issues seem to be too high of a PH? Water – Is my 7- 8ish PH tap water that out of the ordinary? Should I look for an alternative source? What about continuing to add PH down? Space- I think I will do more plant training to create a more even canopy.
I live in California and our tap water is between 7-8 PH. From what I've gathered PH balanced water is a necessity through the whole life cycle of the plants. This is quoted from Royal Queen Seeds The perfect PH value for a cannabis plant The pH scale runs from 1 to 11, with lower numbers being acidic and higher numbers being alkaline. The cannabis plant prefers a pH environment of 5.5 to 6.5. When the pH environment rises in alkalinity above 7.5, the roots are not able to consume the available iron, copper, zinc, manganese, and boron ions in their vicinity, and when the pH lowers into acidity to less than 6 the roots are not able to access phosphoric acid, calcium, and magnesium because they lose their solubility. If the pH drops to between 5 to 3 with temperatures above 26 degrees Celsius fungal diseases become a threat to the plant. Cheers
I threw away my PH meter long ago. My understanding and experience is that if you are using a good organic soil medium and organic fertilizers it will do all that work for you. I haven't paid attention to PH in years and my plants put out good tight bud. Plants are always healthy. I use a combination of Bio Bizz product line and ACT. ACT to get my soil living and feed the critters with the Bio Bizz products which in turn feeds the plants. THROW AWAY YOUR PH METERS!!! ...or at least put them in a drawer in case you think you have some messed up soil and need to test it. Its possible that a bad ph locked out nutes and you you came up with a nitrogen deficiency. More likely your soil just ran out of nutrients. Were you using anything to add nitrogen to the soil? Most soils will be good for 30 to 90 days, then you must feed the plants, not just water. I don't know the FFOF soil specifically. My recommendation is find a good organic soil mix and use a trusted organic fertilizer. Read about ACT. Read allot of Elaine Ingham in regard to soil biology. event if you dont choose to use ACT understanding the food web is critical. ACT (and I use neem every two weeks) will keep pests under control even in very hot weather.