Simpleleaf's grows

I took a pic of my latest bloom, the trichomes are telling me it's ready to cut. I plan to let it dry out for another day or two and continue studying the trichomes to insure I'm seeing the amber that I think I'm seeing. These plants will likely be cut and hung to dry in the next few days.



The plant is in its 7th week, Green Crack. I didn't expect it to be ready yet.

This grow had some unfortunate mistakes. I lollipopped to reduce popcorn buds. It was my perception that stripping it during bloom stalled bud growth for a couple weeks, so next time I'll likely strip it earlier. This is the first grow where I've used 0-3-3 nutes during the last 2 or 3 weeks. Apparently, the potting mix holds quite a bit of residual N, as I'm still not seeing a lot of yellowing yet, just a little.

These two plants got started with a severe fungus-gnat infection (my sanitized potting soil got infected during storage before use) and which was cured with 1/4 cup of 35% H2O2 per gallon of nutes, with irrigation intervals no longer than every 5 days (to break the gnat's life cycle). I was pretty happy that the peroxide worked as well as it did.

Because of that gnat infection, I now treat all my potting soil with a large volume of boiling water the day before I plant in it, let it drain and cool overnight.

If you desire to comment, feel free to do so here.

I think of harvest day much like red-pepper day. On that day I bring home from the market 12 to 14 red peppers. After I put them in the fridge, they'll begin to rot within 10 days or so. Thus I've found it's best to clean them within a few days, that means wash and remove the stem, pith, and seeds, and cut into 1 or 2" square pieces. It is a tedious task. Once chopped, they can be put in a plastic bag, sealed and frozen and saved for months in a chest freezer, thus saving them until I'm ready to make them into sauce.

Harvest day is similarly tedious even while the smell is intoxicating. Gather tools and cut a few branches, then trim them of fan leaves and some of the sugar leaves, finally hanging them to dry. Occasional alcohol cleanings of the shears or scissors is definitely helpful. I'm not a particularly good trimmer, but it ends up smokable when sufficiently dry.



The bloom-tent lights have been unplugged for 4 days, and will remain off until the next bloom, and I'll probably spray the inside with a bleach solution in the next few days just to be safe.

I am disappointed in the lollipopping, I was hoping for fewer popcorn buds, which add to the tediousness of trimming. Perhaps next bloom there will be improvements in my technique, I'm gonna try it at least one more time, I'll strip more, and earlier while still in vegetative.

The plants in the vegetative closet are being trained, and right now are being regularly pinched. They will take longer to grow to a size ready to bloom, but they'll be flatter at the top. This picture was taken a few days ago.



Since the above photo was taken they have developed a magnesium deficiency, so I'll be putting a fixed amount of magnesium sulfate, 1.25 g, per gallon of nutes, rather than having it in ratio to other NPK ingredients.

I'm now making the nutes slightly stronger than what I want (I make a gallon at a time), so I dilute until I get to 1300 EC (sometimes called 1.3), that's the EC I'll probably use for vegetative growth, so 1.25 g of epsom salts could get diluted down to 1 g per gallon after the final dilution and possibly end up with 1 1/3 gallons.

In my fertilizer formulas, I've been using calcium hydroxide (hydrated lime) as pH raiser, but I've noted it wants to layer itself on the bottom of the nutes jug, requiring me to shake it before using, so I'm switching to potassium hydroxide to try. I may go back depending on results, but it should be fine.

I read in a science report not long ago that sodium hydroxide has 8 times the alkalizing power of calcium hydroxide. I wonder if it's similar for potassium hydroxide? So I take the current calcium hydroxide percent (from my formula) and divide it by 8 to calculate the dry KOH weight. I always make a pH measurement of final nutes to insure it's close enough (also an EC reading and dilution to desired level).

Recently, I calculated that I needed to weigh out 0.007 g of KOH for 1 gallon of nutes. Hahahaha. I do use an inexpensive 1/1000g scale, but I know the weighing error would be potentially very large on that small of a weight. So, I'm making a homemade pH-High solution. 1 gram of KOH per 1000 g sanitized RO water (boiled and cooled), and putting it in an old shampoo bottle which was thoroughly cleaned, and adding a cap that has a quick opening squirt nozzle for convenient dispensing. I'll keep my existing formulas to calculate the dry KOH, but to calculate the weight of pH High solution, I'll additionally multiply by 1000. So, from my existing formulas, 0.007 g of KOH x 1000 will become 7 g of the described liquid pH High. In fact, I guess I'll put that on the bottle label, "KOH weight x 1000 = pH High weight".

"pH High
"KOH weight x 1000 = pH High weight
"Ingredients: KOH, dihydrogen monoxide

I've been wondering if that solution will develop mold or some kind of growth? If anyone knows if it's likely to grow something in long-term storage, feel free to let me know!

I'm thinking it may need some potassium sorbate. In California, potassium sorbate is a cannabis-allowed pesticide. It's used in quite a few food products as a preservative and anti-mold agent. Nope, won't work, it's most effective below 6.0 pH.

This harvest is still curing, not yet ready to smoke. I open the jars everyday at this point, and close them back up after a few minutes.



The jar on the left are all popcorn buds, the two half-full jars on the right are thumb-sized nugs. They wouldn't quite fit in one.

My vegetative plants are infected with fungus gnats again. Sigh. Now I'm adding 1/4 cup of 35% H2O2 in about a gallon of nutes, and I will continue that treatment for over a month, irrigate every 5 days for about 6 weeks. Supposedly kills their larve. I guess I'm gonna have to treat the household drains as well on a similar schedule since the gnats seem to be attracted to them, run the hottest tap water down the drain, followed by boiling-hot pan-boiled water seems less expensive than hydrogen peroxide. And they're attracted to pet's water dishes, so those also have to be throughly cleaned and refilled on fungus-gnat-treatment day. I put it in my calendar and I get notices that it's a day to treat for fungus gnats. Damn, I was just refilling a teapot at the kitchen sink, there's an adult fungus gnat flying around!

When I'm done with the treatments a month and a half from now, I'll put a tablespoon or two of earthworm castings as a potting mix topdressing to hopefully reinoculate the potting mix, maybe make a gallon of worm-castings tea and irrigate with it. Could earthworm castings have been the source of the gnat infection?

"the protective effects of the worm castings will help prevent diseases and keep fungus gnats under control."

Hmm, I actually forgot to add worm castings in this last batch of potting mix. When I did use it a few seasons ago, I didn't have a problem with gnats. I guess I need another list of *ingredients to include in potting mix* so I don't forget on potting-mix mixing day. If that doesn't fix fungus gnats next season, then I'll have to include some diatomaceous earth in the mix. I'd rather not have to continually use H2O2, it's relatively expensive.

My vegetative plants have some curious yellowing, beginnings of yellowish splotches. One of the oldest leaves is mostly yellow, with a dark stem. I posted a pic in Marijuana Plant Problems and asked for suggestions. From diagnosis charts I've collected over the years, that appears as either iron or sulfur deficiencies. My nute formulas are based upon hydroponic tomato fertilizer 4-18-38, that I have additionally supplemented with calcium nitrate, epsom salts, MKP and sometimes MAP to alter NPK ratios; and a pH adjuster, in the past I've used hydrated lime, but I've moved to KOH.

According to the Aquaponics Association, potassium silicate and calcium carbonate are preferable chemicals for pH Up. Interesting. I know I've seen members here mention potassium silicate, though I don't believe the mentions were in the context of pH adjustment, rather the addition of silicates.

My formulas are weight-based notations, as I've cut down the EC (fertilizer strength), there's as little as 1/5 the weight of 4-18-38 required for a full dose of micronutes, so I supplement the missing portion with a corresponding portion of soluble trace element mix, S.T.E.M. Upon rereading the S.T.E.M. label, I can increase its strength 50% and still be a label recommended amount, so that will be my first stab at correction, along with 2 other adjustments.

Here's an interesting little factoid I did note in the course of troubleshooting this plant's distress. Peter's S.T.E.M. powder uses metal sulfates, while their liquid S.T.E.M. uses metal EDTAs, i.e., chelated metals. I'm using the powdered sulfate type, so unfortunately iron and manganese are less available at higher pH than if they were chelated. With the items I currently have on hand, the gallon of B-1 is my only existing source of iron EDTA which is supposedly available at up to 7.0 pH.

My last irrigation the nute's EC was diluted to 1300 (µS/cm), but my last runoff had a final measurement of 2100. Therefore, for next watering I'll reduce nutes EC to 1200, hopefully so that runoff should be at or below 2000.

No matter how carefully I measure the powders for a gallon of nutes, the resulting EC seems to vary ± 100 µS/cm. Therefor, I aim to initially mix it (per gallon) slightly stronger than desired, and dilute to desired EC, always giving me somewhat more than a gallon.

I was running the pH of vegetative formulas somewhere around 6.3 to 6.5, my pH meters aren't that accurate and different ones give me somewhat different readings (I use two at the same time which gives me a range, and I recalibrate between every measurement). Given that the powdered S.T.E.M. only uses metal sulfates, I need to lower that to 6.0 to 6.3 pH for better availability to the plant. This last fertilization several days ago I lowered the nute's pH, maybe as low as 6.0. One meter says 6.0, the other 6.3, so hopefully it's somewhere within that range.

I have also replaced the calnit with a 50:50 calnit/ammonium sulfate mix, which shouldn't be as alkaline forming, and will supply more sulfur. So, lots of options, first I'll try what I can without additional purchases.

➤ Too little S.T.E.M powder (now increased to highest label-recommended rate, but this is not chelated iron, only metal sulfates)
➤ Lower the pH of vegetative fertilizer solutions to nearer 6.0 (so existing iron sulfate is more available). Done henceforth within limits of imperfect pH-measurement tools.
➤ Drainage pH was higher than 7.0 pH, which is too alkaline, nor do I add lime to my potting mix, so I presume that is all from alkaline forming nitrogen. I probably want drainage pH somewhere around 6.0 to 6.3. I've replaced some calcium nitrate with ammonium sulfate for a less-alkaline and more-acid nitrification. My first value is roughly 50:50 calnit:ammonium-sulfate, but I need to go through at least one irrigation cycle for the acidification or nitrification to occur and hopefully be measured as a lower drainage pH. That will also up the sulfur content, in case it is sulfur and not iron deficiency. I presume there will be further ratio changes, I'm hoping that whatever ratio is found will work similarly for all my vegetative formulas.

A further tactic I could implement:
➤ Switch from the newer 3-1-1 (NPK) formula to a 3-1-2, the idea being the higher potassium should help iron absorption, from Mulder's chart, synergy between potassium and Fe.

I've recently learned of Iron DTPA, which is claimed as actively-available at higher pH values than EDTA-chelated iron. That may go on a purchase-wish list along with potassium silicate.

In tracking down the source of this vegetative nute problem, I found the Peters S.T.E.M. powder is perhaps the cause of the yellowing, nutes with lower pH and less alkaline forming N will hopefully fix it. I'm considering purchasing EDTA, to chelate the powdered S.T.E.M. sulfates myself during mixing. The longer term problem I'm perceiving is that during bloom, optimal pH is higher than for vegetative, so I will need to find a way to insure micronutes are all available to the plant during bloom cycles.

This has been an interesting problem. 4-18-38 uses EDTA-chelated micronutes. It is supposed to be used at a rate of 2.4 g/gal. In my NPK-modified mixtures, as I've reduced its portion for reasons of EC (2.4 to 0.5 g/gal) and supplemented the associated micronute losses with Peters powdered S.T.E.M, I downgraded micronutes to non-chelated sulfate forms, of which iron and manganese both begin to lose absorbability above 6.0 pH.

It's always nice to understand why a growth problem occurs!

As I'm continuing to think about this, purchasing some EDTA and chelating the micronutes myself seems a reasonable course of action. If I can get drainage pH to the perfect zone, 6.0 to 6.3, chelation probably won't be needed, but I've read that bloom has a higher optimal pH range, 6.5 to 6.8 or thereabouts. So unless I figure out how to get micronutes available at that higher pH level, then my blooms will be less than optimized at best. Thus the desire to chelate the metal sulfates! An alternative is to obtain Peters Liquid S.T.E.M., but they don't sell small quantities, their 2.6x gal jugs are for huge commercial outfits growing lots of plants, and I can't justify purchasing that much at once.

I had a little fun trying to chase down information about chelating micro nutrients.

Instructions for making iron EDTA
[begin quote]
1. Dissolve 7.45 g of disodium EDTA (Product No. E6635) in 900 ml of tissue culture grade water. A clear solution is obtained in 20 minutes at room temperature (25-27 °C).
2. Gradually add 5.52 g of ferrous sulfate heptahydrate (Product No. F8263). A clear yellow solution is obtained immediately.
3. Store the iron chelate stock solution in an amber bottle to protect it from exposure to light.
4. Use 5 ml of the 200 X iron chelate stock solution to prepare 1 L of culture medium requiring 27.8 mg/L of ferrous sulfate and 37.25 mg/L of disodium salt of EDTA (e.g., Murashige and Skoog, 1962; Gamborg, et al., 1968; Lloyd and McCown, 1981).
[end quote]

I ordered a small batch of disodium EDTA dihydrate, https://www.frontiersin.org/files/Articles/564220/fsufs-04-00106-HTML/image_m/fsufs-04-00106-g001.jpgbut I won't get it for a month or two. Once I get it, I'll try chelating the micro nutrients. I have no idea whether it will work, since multiple nutes are in Peters powdered S.T.E.M.™ I won't use the water ratios mentioned above, as I want my existing formulas to work the same. That means I'll do what I did with KOH, but instead of multiplying by 1000, I think 100 will be sufficient: S.T.E.M. weight x 100. When making a gallon of nutrients at a time, I'll have to weigh out about 7 g of liquid micronutes. I have a month or two to let the idea simmer and work out the details, at least until the EDTA arrives.

In the course of searching for chelation information, I found some interesting articles of relevance to growing plants, .


Make sure you check out the cool image, Figure 1.

This next article was helpful in regards to acid- or alkaline-forming nitrogen ratios:

The info which was of relevance to my search is summarized in their graphs, peak growths occur at 25% or 50% ammonium sulfate (AMS) when combined with calnit. A search indicates orchids like 5.5 to 6.5 pH, so that's only a little more acidic than cannabis when grown in soil. Based on this information, I cut back my formula's AMS to a much smaller portion for the next two waterings.

I watered my vegetative plants for the second time with the newly tweaked formula yesterday, hoping there'd be a decrease in the drainage pH. For the last two waterings I had changed my nute formula so instead of 704% calnit as the major source of N, it was changed to 300% calnit and 310% ammonium sulfate (AMS) (that's what my spreadsheet said made equivalent N). The drainage pH was 6.7, so that's definitely a decrease from 7+. Based on the article above, I decided to significantly reduce the AMS to 104% and calnit increased to 586% (as I write my nute formulas, which are similar to baker's percents), and that will be the nutes for my next 2 irrigations which are about 5 days apart. The plant has been looking better (photo below), although the deficient leaves won't ever recover, the yellowing stopped spreading. The newer leaves are a nice shade of green. The yellowing, which apparently was a cascaded nutrient lockout, probably N, initially caused by magnesium deficiency, appears over for the time being. That magnesium deficiency was unintentionally caused by me.

7 days ago:


This morning:


Not bad for 7 days. In spite of the growth, those plants still have fungus gnats flying around them. I'm at about 2 weeks of H2O2-drench treatments. Minimum treatment time is 34 days, I think, so almost halfway.

No photos today. I found the info I was looking for, "Knowing that ammoniacal nitrogen drops pH three times faster than nitrate nitrogen raises it, the water-soluble grower can mix ammonium sulfate with calcium nitrate and/or potassium nitrate to achieve a 1:3 ratio of ammonium to nitrate nitrogen. As plants uptake these two nitrogen forms, the opposing pH pressures cancel each other out, resulting in low to no pressure on pH."

That was exactly what I wanted to know, but it took awhile to find the information. I'm guessing a 1:2 mix would be useful for drainage-pH down pressure, as might a 1:4 mix for drainage-pH up pressure. The 50:50 mix I tried lowered drainage pH quite fast. When I added the needed cells to my spreadsheet, the ratio was 1:0.73, less than 1:1. As soon as I began to wonder whether the drop would continue, I lightened up the AMS, as I didn't want to risk going below 6.0, and I'm not sure I want it that low. I'll be happy to get 6.3. -- perhaps some day.

I had planned on chipping pine needles outside today, but rain occurred instead! So I trimmed some lower leaves on my two Green Cracks, I guess a partial mainlining, and that led me to think I should spread the branches out some more. While I still used some of my bailing-wire stakes which probably contribute iron oxide to the potting mix, I also tried insulated copper building wiring, and I'm pretty happy with the result, though when I snapped the pic they hadn't yet repositioned their leaves to the new light angle.



The same two plants back on Oct 16:



The H2O2 treatment for fungus gnats appears to be failing. Tomorrow is nute day, and I'm gonna add a couple teaspoons of White Lake diatomaceous earth to the nutrients before irrigating, I'll aim for a teaspoon per pot, and will continue that for the next few irrigations, until I get some kind of signal that's enough. I'll also continue with the H2O2 treatments, just in case it is having some effect.

Yesterday, Oct 28, 2021, I moved my Viparspectra V300 to my vegetative closet (it has a lot of blue light), and the 9-band generic LED light with a lot more red LEDs into the bloom tent. Why? Because I wanted to reduce the bloom tent's blue light relative to red.


Yesterday was an unusually hot and dry day, this morning I woke up to find my plants with the beginnings of wilt. Watering day wasn't scheduled for another 2 days, but that's what the heat and dryness does. So, they got pH'd water, the prior irrigation was nutes.



They still have fungus gnats, but populations don't seem to be increasing, that may be the first signal that the DE is working. Each pot has now had 2 teaspoons of food-grade DE added, applied via mixing with irrigation water. PH'd RO water is 160 EC, drain EC was 700, while drain pH was a little acidic at 6.0. To compare, the last irrigation with nutes of 1300 EC, drain EC was 1900. It seems the water always picks up 500 to 600 EC units just passing through the potting mix.

After I had surgery, they gave me those nice 3-sided urine measuring cups to take home. They are ideal for hand watering and measuring mL.

Yesterday's heat and dryness also provided a nice day to paper bag my last harvest for another 15 minutes, and now I've got humidity down to 67 to 68%. They need only a little more and I'll consider them cured.



Unrelated to cannabis, after some rain, I found these mushrooms growing in 2-month old bougainvillea mulch in my yard. They lasted 1 day. I don't know much about mushrooms, but I hadn't prior seen this type growing around here.

My plants had a week of less than ideal growth. The good news is the fungus gnat population appears much decreased, although not yet eliminated. Each pot had a total of 2 teaspoons of D.E. added. Then I received a strong signal that it was time to stop adding more: the claw.



I began to panic. I switched back to my blurple light, as the problem coincided with the light-fixture change. After taking some measurements, I decided the soil pH had gotten a little too low and was causing what appeared to be magnesium and calcium deficiencies. Also, the drainage EC had risen to over 2600, in spite of having recently been flushed.

After some more flushes, a decrease to 600 drainage EC, and a very light fertilization with 3-1-2 alkalizing formula (no added AMS), here she is this morning.



It seems the crisis is over, the plant is on the road to recovery. I'm dropping the relative NPK ratio of 3-1-1 in favor of 3-1-2, the plants seem healthier with better mainstem growth. I'll also be decreasing the ammonium:nitrate ratio from 1:3 to 1:6. I'm still hoping to eventually find a value that results in 6.3 pH in the potting mix I use. 1:3 seems to *maybe* make it slightly too acidic.

The damage to the plants was permanent. I'm thinking about removing the damaged leaves simply because I don't enjoy looking at them. Under 6500K light for the photo (plus camera flash), the damage doesn't look as bad as when it's under the blurple. I haven't been rotating the plants as is commonly done, I'm pretty lazy about stuff like that. So the plants have been pretty much fixed relative to the lights and reflective walls.



You can see the plant on the left has the least damage. It has mylar very close on one side only, taped to the sliding door. The other end of the closet is for storage and there's no reflective divider. You can see the leaf damage is pretty much limited to the circled area. The plant on the right has some damage outside the circled area, and it is closely surrounded on two sides by mylar (solar blankets taped to the wall), so it has a little more reflection close to it. The circle I drew is roughly the central area of the LED unit above it. I never thought to measure its height above the plants when I put the V300 in for a few days, but it was the same height as the generic blurple, approximately 2 feet from the plant tops. Ultimately, I don't know that the light damaged the plants. It could have been excessive acidity, or something else. These two plants have gotten some experiments with lower EC nutes and a 3-1-1 formula inspired by zamnesia (I think K needs to be higher than P for vegetative, but it was fun to try). So, the plant damage very well could be from multiple sources of stress.

The V300 has been unused since I pulled it away from these plants. I'm thinking of replacing it with another light. It was anchored in my bloom tent for a few years. As a bloom light, when mixed with another generic blurple with a massive amount of red LEDs, the plants did okay. However, it's also been my sense that bloom growth has not been as full or robust as it could be. So, I'm thinking of buying another, and packing the V300 back in its box to sit unused. I'd purchase another generic blurple, but they are no longer sold in the same LED configuration. C'est la vie.

I'm also thinking of making these two Green Cracks the last, not cloning them again. Maybe not growing for awhile. Just something I'm considering. Or maybe getting another strain. Not sure.

I took a pic of the same plants under the blurple which the vegetative plants seem to love. Rather than splitting the two photos on different posts, I put it side by side with the picture from the prior post. The damage is more visible under the blurple.



Besides removing the V300, I increased magnesium sulfate in my nute formulas from 1.2 g/gal to 1.5 g/gal. I also moved back to the 3-1-2 formula that I had used since 2018 and dropped the 3-1-1. Mulder's chart says there's synergy between K and iron, and some of those light-burned leaves seem to mimic iron or sulfur deficiency. I trimmed the damaged leaves this morning.



I still have a few fungus gnats, but the population is vastly reduced. Because the D.E. seems to stay in the potting mix, I decided to allow longer intervals for drying. After 11 days without irrigation, there still was no wilt but I decided they needed water. My drain EC was 1300 microS/cm, with 1200 going in. Last irrigation drain EC was also 1300. This was quite different from when the watering interval was 5 days. Under that irrigation frequency, drainage EC built up 500 to 600 EC units with each irrigation, eventually requiring a flush to reduce. The axiom seems to be, "A build up of drainage salts may indicate too-frequent nute irrigations and an insufficiently long drying interval."

The plants seem to have difficulties of various kinds when growing at the acidic end of recommended pH levels, it seems to make them more sensitive to their environment. In the future I'll be moving my target pH for vegetative to near 6.5, for both nute solution going in and drainage pH, my goal is for both to match. Since I can manipulate drainage pH, might as well, in spite of the frequently RIU reposted advice of, "Runoff pH is useless". Right now I'm on 6.3 for both, that's with 6:1 nitrate:ammonium ratio. Unless I decide to pour my other gallon and a third of nutes on some plants outside and make another batch, the plants will continue with the 6.3 pH solution until it is used up in about 2 or 3 weeks.

~~~

My other hobby is cooking. I made this salty-vinegary chile sauce last week, it's a monthly ritual. I call it Deep Red Hot Sauce with Black Flakes.



The sauce is excellent on pork or beef once you acclimate yourself to its heat. Think taco-shop red sauce. The black flakes are made from the dried-peppers' seeds blackened in an oil-free skillet over high heat. It is best to do this on an outside stove, and stand upwind, the seeds' smoke is extraordinarily acrid, and if you're using an inside stove without a commercial-kitchen grade exhaust hood, the fumes will probably drive you outside to fresh air. The black flakes addition to the sauce at the end of hot blending adds a nicely-charred sub-dominant flavor.

Fungus gnats are still present, but only one or two. However, the yellowing is continuing to progress.



You'll probably notice they were just watered. During this process I noticed some EC irregularities, which caused me to question the integrity of the EC pen I'd been using. The instruction manual mentions calibration, suggesting it is possible, but included no instructions to calibrate, so I never tried. I picked a 20+ year old PPM meter off my shelf which had a calibration screwdriver but had never been calibrated.

Do-It-Yourself Homemade TDS Calibration Solution | Rollitup

I calibrated that PPM meter and I will be using it from here on out instead of the EC meter, which is going into retirement. Besides one display digit which wasn't showing all "legs" of the number, it was also reading 250 to 300 PPM too high, thus all my nutes were too weak by that amount, that's the same as 500-600 EC units. When I thought I was irrigating the plants with 1200 EC nutrients, I was only irrigating with 600 EC nutes.

The plants didn't have enough fertilizer! They've been screaming "Feed Me! Feed Me!"

Today they got fed with 722 PPM solution (doubles to 1444 EC equivalent). Again I cut off all the damaged fan leaves. I'll find out in another 7 to 10 days (the next irrigation) whether they stop their yellowing.

They won't grow very fast this time of year in late fall, inside the ambient temps get down to 68 °F and won't warm up much past 75 °F during the day. I have a heating mat, but these particular drip trays are double-walled with airspace inside, so they are insulating so I think the heating mat would be a waste of energy. I have no existing way to apply heat, so at best they'll grow slowly.

I've been daisy chaining my grow journals. When I started this one, I should have put links to the prior journals at the top of the first post, but I didn't. So, here are some old grow journal links:

Blue Dream and Green Crack, 2nd bloom, Oct 6, 2018
Blue Dream, Green Crack, and BlueBerry at 5 weeks, Sep 11, 2018
Blueberry, simpleleaf's grow 3, Feb 12, 2019

My vegetative plants seem to be on the mend.



I haven't seen a fungus gnat in a few days. It took the diatomaceous earth between 3 and 4 weeks to have this effect, each pot has had a total of 4 level teaspoons over that time period. I've stopped the H2O2.

The torn leaves at the top are due to some fimming I did instead of pinching back. The yellowing leaf tips are curious, they appeared after an 11-day drying interval, I had been watering every 5 days when using the H202. I'll probably be watering every 7 or 8 days.

I'm using a 6:1 ammonium:nitrate ratio in my nutes. I'm going to try 10:1, perhaps on the next watering next Friday.

The lighter green growing tips have returned. I believe that's a response to the change from 3-1-1 to 3-1-2 NPK. It's currently getting 1500 µS/cm nutes of 6.3 pH. My last irrigation was with some 6:1 and some 10:1 nitrate:ammonium nutes, so I can't draw any conclusions about any resulting runoff-pH change.

It appears there are light artifacts from the camera flash reflecting off the solar blanket walls.

I intend to try either the Viparspectra V300 again, or another LED I have, now that the plant has responded positively to the increased nutes and is looking healthier. I'm trying to find a light I already own that will work okay in vegetative, so I can move the light they're currently under to the bloom tent.

Here's the blurple light they're currently under, and I really wish I had bought more than 1. My plants have always grown well under it, but I've checked and double checked, it's no longer available in the precise color ratios in the competitive markets:



As of moments ago, I swapped lights with a "Hyber Grow". This light has not been used much, I know it has created magnesium deficiency symptoms in the leaves when I've used it in the past. If that's all it does, perhaps I can increase the epsom salts to compensate.



These lights are all old technology now.

I ended the experiment with the Hyber Grow light on day 4. I'm not sure whether it burned the plants, but they became progressively sicker on each passing day. The first symptom was drooping, and by the second day, continued drooping, even in early evening after the warmth of the day when the leaves typically picked up a little. I started to see the beginnings of magnesium deficiency in the upper leaves, and some yellowing spots, reminiscent of too little nitrogen but at the top of growth, so possibly light burn. I think the confirmation to end it occurred on irrigation day, it hadn't consumed as much water, only 75% of what it should have consumed. Sigh.

I didn't think it was a good "full spectrum" blurple when I tested it before, that's why I haven't used it. It's certainly possible to chase the symptoms with nute adjustments, maybe a healthy balance could be found, but I didn't want to. The plants are back under the multi-colored LED unit.

Here's a photo under 6500K with flash (and flash artifacts, mostly on upper-right plant nearest the walls' corner). It doesn't look too bad. The burple pic under which the symptoms are more visible is out of focus, so I won't post it.



I'm not sure when I'm going to put these two plants in the bloom tent. When I move a plant that's been under 24/0 out there I continue vegging for about a month on 18/6, get it all trimmed with some new growth above the net, then switch to bloom. I have a little maintenance I need to do in there with the ceiling-to-floor circulation fan, the ducting is cracked open, I guess that needs to be looked at and repaired in the next few days.

No pics of my plants today. I'm trying a new light as of yesterday, it was less than $30 and I thought I'd like to try it. If the plants like it, I might buy a second, since it draws about half the watts of the prior blurple, less than 50. This one is a yellowish light, it seems popular these days. One flaw with the light is the location of the driver, it is screwed onto the backside of the LED metal, so it runs fairly hot, almost too hot to touch. If it proves a good light, I might try to move and isolate the driver from the LED heat.



Today was irrigation day. Last irrigation a week ago the runoff salts were too high, >2400 µS/cm. I diluted the leftover fertilizer from last week's irrigation to 500 PPM or 1000 µS/cm, added Vitamin B-1, which includes EDTA-chelated iron, and pH'd it to 6.3.

Yesterday's irrigation began with 10:1 nitrate:ammonium, it was finished with 20:1, a mixed irrigation from which conclusions are difficult to make; runoff pH was about 6.3 and 2000 µS/cm, with roughly 20% runoff.

I added 1 teaspoon of "Vitamin B-1" which includes 0.125% of EDTA-chelated iron, manganese, and zinc. The label calls for 1 to 2 tablespoons, I started with 1/3 of the recommended minimum. I may increase that to 2 teaspoons next irrigation (in a week). I will soon add DPTA-chelated iron. This iron strategy should eliminate any question of whether there is or is not enough iron available in the nutes. Per the label, the Vitamin B-1 brand I have on hand adds to zinc, and I may have too much zinc already, which is said to mimic magnesium deficiency.

The plants look to me like subtle signs of iron deficiency, as well as clear magnesium deficiency. I add magsulf at 1.5 g/gal. Several online sources, including one here at rollitup, recommend a teaspoon of magsulf per gallon, which is closer to 5 g/gal.


Next irrigation I'll be doubling the Epsom salt (magsulf) level to 3 g/gal. I'm even considering adding more magsulf to my remaining gallon of nutes, and irrigating tomorrow again.

I received my iron DTPA today.



The label said, "FeHNaDTPA" which according to this patent, "D-FE-11 is Dissolvine® D-FE-11 made by Akzo-Nobel it is the iron(lll) hydrogen sodium salt of diethylenetriaminepentaacetic acid, FeHNaDTPA". That's enough information to find a usage label. Problem is, that usage label does not indicate the described product has any N. How much to use is now a guessing game. I may ask in the nutrient forum, maybe someone is familiar with it. I'll try a little of it, probably next week, and see what happens.

I should have moved these two plants to bloom already, but I'm caught up in trying to fix this nutrient problem and want them to remain in vegetative until I figure it out and get nice healthy growth. I just watered with nutes 2 days ago. The plants are always happy on day 2 after watering.



On the last watering two days ago I made two changes at the same time, which I'm not happy about, I should have only made one change. I added a teaspoon of Vitamin B-1 primarily for it's iron EDTA and doubled Epsom salts from 1.5 g/gal to 3 g/gal. I have one more gallon of this batch already made up for the next irrigation, I don't want to waste it. I may decrease Epsom salts back to 1.5 g/gal when I've used it up next week. I've decided this is primarily an iron problem, at least it seems more likely than Mg deficit because yellowing and interveinal chlorosis is on upper leaves indicating a mobile nutrient. I'm pretty sure the new leaves are now greener. If my perception holds up over time and because I made two changes, I won't know if the Mg increase or iron-type change was the fix.



A third change that was made was the new light. The plants have been under it for 4 continuous days, and so far no light damage. My sense is the plants like it well enough.

My plant is looking greener on the newest leaves, so either the addition of "Vitamin B-1" or increased Epsom salts seems to be some of the solution.



I'll water either Thursday or Friday and will delay adding the iron DPTA for a few watering cycles. Instead I'm awaiting delivery of "chelated liquid soluble trace element mix", which will be an upgrade from the sulfate-based micros I've been using.

I also decided to order a small amount of AgSil 16H (potassium silicate), I've been wanting to try it as pH up. According to the following page, that usage of it will fail, but, I'd still like to try it myself.


The DE which I used to help kill off the fungus gnats is also a source of silica (PDF). What are the differences between silicon, silica, silicates and silicone (PDF)? According to one website page I read, one or more brands of potassium silicate are pH balanced, so for my purposes of raising pH, that brand or brands would not have been satisfactory.

The plants seem to like the new light. I think they grew slightly better under the blurple I was using, but I'm happy with this light and will keep using it. That frees up that blurple for sole use in the bloom tent!

I did a quick spreadsheet analysis of the differences between the powdered micros and liquid micros, and decided with respect to the powdered product that zinc at 1 PPM was too high even though it's a label recommended amount for continuous feeding. Further increases in the amount given to the plants was not a great idea primarily due to that high zinc level. A too-high zinc level is suspect for potential lockout issues, but I don't know at what PPM level toxicity begins to manifest. 1 PPM of zinc is greater than any hydroponic formula I can find, including in Howard Resh's book Hydroponic Food Production. The chelated liquid micros have a much better PPM profile, although it appears it may be a bit low on molybdenum.

I finally got around to studying the Dissolvine D-Fe-11 label I downloaded from a merchant's site (which likely is related to the DPTA iron purchased and pictured in a prior post, the ad said it was manufactured by Dissolvine). For root absorption, Dissolvine recommends to mix their product with "Fe-EEDHMA", or a "high quality Fe-EEDHA". Their label also said to mix with urea for better foliar absorption (hmm, does what I purchased contain urea? Is that the source of N on the label? If so, then I'll probably need to increase application rates. The label for Dissolvine which I downloaded didn't mention it contains any nitrogen.)

After reading, studying and highlighting, I came away with the impression it was best used as foliar. Foliar is an application method I do not really like, partly because my vegetative closet cannot have water sprayed in it, and partly because I do not like pumping the spray bottle so many times. Some of it drips down the stem into the potting mix.

My plants look yellowish to me. I didn't cut off any sickly fan leaves after the last watering and didn't use a new nute formula, therefore didn't need to more easily see if the yellowing problem continued or was improved. Here's a couple pics I took on Dec 26 (yesterday), which was 2 days after irrigation.


Today I mixed up a foliar spray and sprayed the plants after moving them to the bathtub so they could be sprayed. The mix I used included only 32 fl oz RO water, 0.1 g of iron DPTA, and two large drops of dishwashing detergent (one drop didn't stop water beading). Because it's a little less water (a quart is about 95% less volume than a liter), the iron DPTA in the spray bottle was mixed to a use-rate of about 0.105 g/L. I only sprayed a few fluid ounces, some of which landed on bathtub plastic.



Those last two photos were taken about an hour after the foliar treatment. How long does it take for the plant to respond to foliar iron?

Although a foliar spray produces quick results, the improvement is temporary because iron will not move into the tree beyond the tissue that was sprayed. New growth emerging after the treatment will be chlorotic.

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I used close to Dissolvine's lowest amount for foliar (0.1 to 0.4 g/L), substituting a quart for a liter of water, but the product I bought, since its label says it contains N, the application rate is likely somewhat higher. If the product was in fact repackaged Dissolvine with no other chemicals added and if the plants are iron deficient, then I reckon in a few days the plants' leaves that were sprayed should become a darker shade of green. Maybe. If the plant doesn't green up, it could also be due to insufficient iron DTPA per volume of water (or perhaps another cause entirely).

If I want to give a higher dose to one or more plants, I could add more to the spray bottle, or I could spray more tomorrow morning. The plants can probably be sprayed several times in a day, but there's no good plant light over the bathtub. A few hours in a low-light situation probably won't harm them, and if it does, they should recover quickly. That's an ambiguous word.

On the topic of insufficiently strong dosages, two days ago my PPM reading on runoff was about 1000 (so 2000 EC), which is about as high as we're supposed to go without CO2. But is that true? Might I be looking at simply not making nutes strong enough?

Another hypothesis is the two plants have been fed too much Zn over too long a period of time. The micros product is being changed as of the next watering to a much lower Zn formulation. If the plants and potting mix are in Zn excess, then flushing may be helpful. My research indicates EDTA or citric acid make flushing more effective, but I'm having trouble determining how much EDTA to add relative to the water. I would not hesitate to use a plain RO-water flush, but will it effectively remove excessive Zn-sulfate buildup in the potting mix?

The following website has a good writeup on how to foliar feed,


I've sprayed my cannabis twice with the same batch of iron DPTA solution. Per the manufacturer, the solution is photoreactive, degrades in light. I've got it ready to use in a plastic, finger-pump spray bottle which lets some light through to the solution, so I'm trying to store it in the dark.

I'm also trying to understand how much urea might be good to add to it. Dissolvine's user recommendation sheet said in a paragraph about urea, "The pH of final concentration should be lower than 7, the final EC lower than 1. Dose rates for a specific crop should be tested first on a small scale."

Because foliar fertilizers are in salt forms they can damage plant tissue if applied at rates that are too high. Generally a 0.5-2% fertilizer solution is recommended.

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I'm a big fan of university publications, the information given is typically reliable. According to that, I can add urea to the iron spray in the amounts of 0.5 to 2%. Thus, 5 to 20 g low-biuret urea can be added to a liter of water (g/L), or more simply, less than 20 g. Maybe I'll hold off on the foliar-applied urea for a few weeks, see what happens with the trace element change and a few sprayings of Fe during the week.

Dec 30 marked the calendar date when 5 days of drying had occurred so, I decided to mix up a gallon of nutrients. I wanted to decrease the drying interval a few days. This time I used the new liquid soluble trace element mix, the prior powdered S.T.E.M. is no longer routinely used.



The liquid is so dark that when used at full strength and is in the syringe it's near impossible to distinguish the end of the dark purple of the liquid, the beginning of the rubber plunger, and the marks on the syringe. Difficult to see and therefore to measure.

I've decided I will have to dilute this, maybe 10x, maybe 100x, not sure yet. Make the liquid much less dark so light penetrates through it and I can see the black plunger and the black gradations on the syringe. The pictured syringe is 1 mL with 1/100 mL gradations, and is open to roughly the amount of liquid needed. Today's 1 1/8 gals of nutes needed something like 0.083 mL of liquid trace elements, a little less than 1/10 mL, and it was difficult even with a magnifying headset to see the syringe's markings. If I had diluted trace elements 10x, then I would have had to measure 0.83 mL, or with 100x dilution, 8.3 mL. I think I might want to try 10x to begin, see if that's enough dilution to make the liquid more transparent to light. That might not be good if it's photoreactive.

With the current darkness, the only way I can think of to measure is to set the syringe before filling it, then use a caliper to measure the finger-end of the plunger to syringe body distance. Then fill the syringe, and squeeze out until the syringe matches the caliper's distance. Kind of tedious to do it that way, so I think dilution of some amount will be a mixing day stress reliever, once the best amount is found, that is. The trace elements are very concentrated. I'm kind of excited about trying them!

Last irrigation my runoff EC was higher than I wanted it, so I mixed nutes to 1200 µS/cm this time. I still think in terms of µS/cm, even though I switched to using a PPM meter. So 600 PPM and 6.2 to 6.3 pH going into the potting mix. 2400 µS/cm out (1200 PPM) and pH out (5.9 & 6.5 pH, different meters, paper said 6.0).

There was lots of salt buildup in the pot, I expected it a bit higher due to the shortened drying interval. Next time nutes will need to be near 800 µS/cm, or less, I have a little less than half a gallon of today's 1200 nutes remaining. I may just dilute it next week to the desired conductivity.

The plants have always looked best on day 2 after irrigation, so maybe I'll snap a pic then. I did pick a few handfuls of yellowish fan leaves off today, and I'll probably do that tomorrow as well.