Oct 22 (DAY 55) continued....
Feeding
The soil's too dry to wait till morning. I'm going have to feed a little before lights go out (14 hours from last feeding. I'll pour the rest in the morning.). They're definitely doing well with the stronger (300+ ppm) feedings. BTW: I'm keeping all the feedings summarized in a spreadsheet. I'll post that at the end of the grow.
This time I'm boosting potassium a little again, targeting NPK ratio 1-1-1.6 (318ppm).
Potassium sulfate (0-0-50). Want 70ppm.
GrowMore Sea Grow All Purpose (16-16-16). Want 248ppm.
GrowMore Amber Humic. 1.2mL/L (medium dose per label)
Starting water = 137ppm created with:
65ppm tap
36ppm gypsum
26ppm epsom
Added 0.116g/L potassium sulfate for 73ppm increase
Added 0.667g/L GrowMore Sea Grow All Purpose for 248ppm increase
Added 1.2mL/L GrowMore Amber Humic for 20ppm increase. Total increase over water: 321ppm (or 341 counting Amber Humic). Total ppm: 478.
Added pinch (1/16 tsp/gal) sugar (for the soil microbes).
Runoff: 1430ppm (3% runoff.).
Note: Lower volume because I spread the feeding over 13 hours. (I.e., they drank some of what would have poured through if I'd done it at once). I like that PPM. Looks good to me (except the volume is too low to read much into it).
Actual NPK ratio 1-1-1.63 (321ppm)
Oct 23 (DAY 56)
Feeding continued...
I poured the remainder of the feeding a couple hours after lights came on. I documented the runoff above.
Oct 24 (DAY 57)
Feeding
This time I'm boosting nitrogen & potassium, targeting NPK ratio 1.31-1-1.51 (335ppm). After that last feeding, they look like they might benefit from more N.
Potassium sulfate (0-0-50). Want 59ppm
GrowMore Sea Grow All Purpose (16-16-16). Want 228ppm
Pennington Alaska Fish (5-1-1). Want 48ppm
GrowMore Amber Humic. 1.2mL/L (medium dose per label)
Starting water = 135ppm created with:
44ppm tap
55ppm gypsum
26ppm epsom
Added 0.096g/L potassium sulfate for 68ppm increase
Added 0.516g/L GrowMore Sea Grow All Purpose for 223ppm increase
Added ?mL/L Alaska Fish for 48ppm increase.
Added 1.2mL/L GrowMore Amber Humic for 27ppm increase. Total increase over water: 339ppm (or 366 counting Amber Humic). Total ppm: 501.
Added pinch (1/16 tsp/gal) sugar (for the soil microbes).
Runoff: 1330ppm (20% runoff).
Note: Much higher volume. I was worried I might be getting salt buildup after the last two feedings with low runoff. It looks good to me. Normally I feed strong, and do 10-20% runoff to get rid of the excess. I don't try to dial it in. I feel it does better with the strong feeding (and modest flush). I think I can feed a little stronger now, and continue with higher volume runoff (at least 10%). I would be looking for 1400-1800. I was only doing low-volume runoff because it appeared they were underfed, and I didn't want to wash away what was in the soil while it was just 830ppm.
Actual NPK ratio (based upon the actual PPMs created): 1.32-1-1.6 (339 ppm)
A word about PPMs:
For the nutrient solution, I'm using an HM TDS-3 meter calibrated to 342 (using HM's calibration solution). For the runoff I'm using an HM EZ-TDS calibrated to 1000 (using 1 gram of ordinary salt from the kitchen table dissolved in 1 liter of distill water. Mathematically that's supposed to be 1000ppm. But, it's not pure salt. Has iodine, etc. And, the meters aren't really reading parts per million. They're reading conductivity. Different minerals conduct better or worse, I believe.).
The reason I mention that: I have 4-5 TDS meters & have noticed if I calibrate to something 1200ppm (1.2g salt in 1 liter distilled water), then measuring a 300ppm solution will be about 80ppm higher (than if I calibrated to the real 342 calibration solution). Likewise, if I use the 342 calibrated meter to measure the 1400ppm runoff, it will read 1200ppm. (I might be exaggerating. But, it will be off a fair amount.).
I usually use the 1g/L salt (distilled water) solution, but will do 1g/gal to get 264ppm (instead of 1000 @ 1g/L). Or, 1g in 2.92 liters to get 342ppm (in theory). I also have HM's 1000ppm calibration solution. My 1g/L salt solution comes out 5% higher than the official solution.
Anyway, this stuff doesn't matter much if you're doing your own thing, just comparing one feeding to another. The only thing that might matter is if you use the same meter for nutrient solution and runoff. You'd have to know that it will be less-accurate the further from the value you calibrated to. Additionally, if you discuss PPMs with other people, it would matter how you (& they) calibrate (which range, whether it's official solution, or DIY salt g/L = 1000 "close enough" reference, etc.). The interesting thing about the salt & distilled water method is that it's cheap; you can make various reference solutions (strengths) for yourself, and see how your meter varies (the further you go from what you calibrate it too). You could use just one meter and know you need to add or reduce the displayed value when measuring further away from what you calibrated it to. You need fairly accurate water-volume measurement, and a jeweler's scale (I like the Horizon Pro-20B. Also the GEM-20. Both are on ebay & Amazon, inexpensive, can be recalibrated.). Once you make your solutions, they'll last a long time.
I think this is one thing which EC meters are better for, but not really either. PPM meters are measuring EC, converting it to the ppms of some hypothetical dissolved element (when elements have different conductivity, I think). PPM meters are more of a "rose-colored eyeglasses" view. Seeing the EC would be more direct. But, EC 1.2 vs 1.3 is 70ppm (theoretically, if all the dissolved particles were sodium chloride, or whatever). For the way I fool around with 20ppms of something or other, that wouldn't work well for me (unless EC meters display two decimal places. I've never seen one. Maybe they do.). But, then again, who knows how accurate my meter's measurement is down to that granularity. Maybe I just think I'm controlling things that much. I don't know. I've done it for 6-7 years. My mind thinks in terms of ppms (and NPK ratios).
Oct 25 (DAY 58)
24 hours after last feeding
I took these photos 24 hours after the last feeding (and 3 days since the last photos). Space remaining:
I'm keeping the tent closed now (starting late yesterday). It's pretty obvious that the back of the tent has filled in a lot, but the front hasn't. That must be the reflective wall. With the front open, they don't get that boost.
It may be too late to fill in. They're probably past much of their stretch now. But, it would help the bud development. (I've never noticed the reflective material make much difference with normal-shaped plants. I usually sidelight around the plant more vertically. This seems different because the plants are growing sideways. It seems obvious to me that the reflective material is making a difference.).
Also, you can see plants 4-6 (right half of tent) look obviously more thriving/energetic/enthusiastic/happy. These are the closeups:
1-3
4-6
I'm really thinking it's the light (the 3000k "wide surface" bulbs). Maybe the rougher transplant for 1-3 stunted them. I've never seen shock affect plants that much. (The first transplant from seedling cups to 20oz cups, the seedling soil was very sandy and fell apart in my hands. I expected the plants to die within 4 hours. They were thriving after 4 hours.).
So, I will buy 2 more of those Philips 16w? (I forget) 3000k "wide surface" bulbs tomorrow morning, and put them on the left side of the tent. That will indeed answer the question. If those lights are doing something spectacular, then it should be evident very quickly on the left side.
LIGHTS
The top fixtures remain as I last documented. (I haven't changed them to be what I showed in the diagrammed plan for flower a few days ago.).
The Cree 15w 2700k A19 bulbs (three of them on the tent legs. Rear left & right corners, front middle pole) are too bright to look at (as are any of them). But, a few times I've seen distinct red LEDs mixed in with whites, which reminds me of the old Area-51 RW-150 fixture (which I still have if the cannabis museum of history needs one). That fixture's whites & reds were considered exceptional performers.
I've also faintly detected blue diodes (out of the corner of my eye). When feeding yesterday, I saw one of those Crees reflected in the water-covered black runoff tray. I could definitely see blue LEDs spaced among the red and white. They were light blue. Not a cool white (6500k), but more blue. Not "blurple" blue either. Maybe 8000k? 10000k? Much lighter than blurlple blue. But, more blue than 6500k. (I think. Maybe it's an optical illusion compared to the reds, maybe it looks more blue.).
Anyway, that's interesting. I can't say I've noticed the plants liking that light better. In fact, I'd have to say that they like the Philips 16w 2700k (which is all warm white, not a mix of colors). I feel like I've seen that a couple times. Or, at best, they're equal. (But, maybe they supply different spectrum which, overall, are better than the plant receiving just one.).
Either way, I definitely have noticed the plants like those 3000k "wide surface" bulbs. That's not speculative. It's strange because they don't
appear to be bright. The more concentrated A19/21 bulbs look brighter (more intense). But, my PAR meter shows really good levels under those "wide surface" bulbs. It must be the way the diodes are spaced out, they look weak.
SCROG
I'm thinking I shouldn't tuck these things anymore (or once more). They're flowering enough now that I feel like they should start their filling out the vertical branch. I think it's possible to tuck them too much into flower. I don't know (buds growing sideways? instead of vertically). Plus, I don't like handling flowering buds. That's always seemed like a no-no to me.
I have 1.5 feet of vertical space above the fixtures. I'm not worried about too much vertical growth now. The point of SCROG is to have a uniform/even/flat canopy to make the most use of light. I want to capitalize on that. But, at some point the buds have to enlarge, fill out in the normal sense. Tucking too long would put them horizontal and perhaps impede the finishing. (I don't know. I've never done this before.). I'm thinking they're close to that point now.
pH
I think user
@hyde said higher pH soil causes more growth/stretch? I can't say I've seen that. Using a fairly expensive Control Wizard soil pH probe (not some cheap thing from Home Depot, but I can't say it's good either. I don't know.). What I've seen is that the soil goes through a range of pH (5.5 to 7) from wet to dry. Even if it starts low, it passes through the good range. If it starts high, it passes through the good range too. (As long as it didn't start too low or high.). It hasn't looked to me like a deterministic value. It's just a matter whether the range is skewed lower or higher. As long as skewed too low or high, it all worked out in the end, I felt.
There could be some benefit to pH'ing nutrients for soil. Fine tuning. I got put off by it because the up/down products are essentially salts. They don't list their nutritional content because they aren't sold as food. But, using them changes the NPK ratio in ways you aren't cognizant of. And then, the downward spiral I found myself in was that I was overfeeding, getting salt buildup, acidifying the soil, causing me to add more "up" -- which added more nutrients to the solution, adding to the buildup, causing the soil to go further south.
I haven't seen a need to pH nutrient solution since I stopped (once I realized the runoff ppms closely track the acidity of the soil; the salt buildup.). If I want it more acidic, I feed more. If I want it more alkaline, I feed less. (I hardly use my soil probe anymore. I used to probe every day, twice a day. But, I hardly ever probe now.). It just seems to all work (knock on wood. Now it's probably going to go to hell after I said that. I always worry maybe I'm just lucky.).