These were my bagseed plants on Day 60 (from breaking ground). They're 3 weeks plus 4 days since 12/12.
I've occasionally tested overfeeding, and some leaves show that (curled, buckled). I've been reducing N. This Kellogg Cactus potting mix is seriously N deficient. I'm down to an NPK ratio 1.7-1-1.5, and I think I've gone too far. The new leaves emerging from the bud look a little pale. I'm going back to ratio 2-1-1.6. (That sounds terribly high N. At this stage of growth in my usual soil, I'd be around 1-1.4-1.8. The ratio 2.1-1.1.8 would be a very high-N veg ratio in my soil. This cactus mix is weird that way.).
The one on the right has suffered the most from my overfeeding experiments. I've attributed that to it being a different strain that doesn't need as much food. But.... one possible difference is that the one on the left had 1.5 Tablespoon/gallon dolomite (Fertilome Hi-Yield Agricultural Lime) amended into it before planting the seed. The one on the right is the cactus mix straight out of the bag.
I was torn whether to add dolomite. I do it as a habit. (I think it can only help.). But, this cactus mix isn't really a soil. It's mostly sand. I wasn't sure how dolomite would do. So, I did one with, one without.
I've been thinking the difference between the two could be that. For example, the runoff ppms for "Dolo" have been consistently higher. If "Nodolo" were being overfed, I would expect its runoff ppms to be higher and spiral higher. Instead, it's tracked Dolo up and down, but always lower than dolo. So, I'm thinking Dolo's higher runoff ppms are due to the dolomite breaking down, releasing Ca & Mg. And, "Nodolo's" not-so-good performance is due to it not having that breakdown (which must result from acidity).
I have a fairly expensive soil pH probe. I should probe both and see if Nodolo is lower ph (which is what I would expect if my theory about the dolomite breaking down, causing higher ppms in Dolo). The probe is 3/8" diameter. I'm reluctant to disturb the soil that much (in these small 1gal containers). But, I'll at least do it in the end, when I harvest. Maybe I'll do it sooner. I'm afraid of stressing the plants if I cause some root damage. If it was a 3gal container like I usually grow in, I'd do it. The probe seems big relative to the amount of medium.
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I'm running about 28w/sq ft of household LED lightbulbs. I have two more 9w bulbs to add as flower progresses. That will put me at 125w total (in a 2x2 space) @ 31w/sq ft.
I usually run about 20-22w/sq ft and they do very well. I want to see how they do with stronger light.
So far I'm happy with it. I'm not ph'ing the nutrient solution. I'm using MiracleGro All-Purpose fertilizer (24-8-16), and now I'm mixing it with MiarcleGro Tomato (18-18-21) to reduce N. (I had to supplement AP with Pennington Fish Emulsion (5-1-1) because the plants needed more N. AP is ratio 3-1-2. They needed about 3.8-1-2.
I'm only feeding about 200-220ppm every 36 hours. The cactus mix is very fast drying. (Too fast. It would benefit from some vermiculite.).
I'm going to grow this again using MiracleGro Performance Organics (11-3-8). That's a ratio 3.67-1-2.67. I think that would be very close to what Kellogg cactus potting mix needs. Plus, it's sourced from organic nutrients. That should be better.
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The more I grow with cheap stuff, the more I think the expensive, elite, cannabis-themed, cartoon-labeled stuff isn't necessary. It's too soon to tell for this grow. Maybe it will taste bad. But, I've grown a plant with MG Tomato, and it tasted fine. I'm more concerned about the cactus potting mix causing a taste issue. It has a dusty/sandy/dry smell (like concrete). It's not a sweet soil smell. Little worried about that.
It's been really fun to grow this one. I have a "system" I follow, which works (and never stretches me to learn to grow again). This cactus potting mix has been a real challenge. I've been experimenting a lot, learning more. Very fun. Yesterday I fed it using water whose base 180ppms came from gypsum and epsom salt. (Usually I mix tap water with RO water to get 150ppm starting water. Yesterday I added enough ppm to RO water for 100ppms, then epsom salt to get up to 180ppm.). Then I mixed 200ppm of the MiracleGro All-Purpose & Tomato fertilizers (for NPK ratio 1.7-1-1.4). The plant seemed to like that. What was surprising is that the runoff ppms went drastically lower. Not sure what that means. The runoff ppms had been hovering around 650-750 (with nodolo being 100ppm higher). They went to 520, and were almost the same.
I'm not going to do that again, at least for awhile. I'm going back to tap water mixed with RO for 150ppm. Give the plants some time to show any results. I'm going to go a little higher with the N because I see some pale green in the new sugar leaves.
Pretty soon I'll supplement with Pennington Alaska Pure Kelp. I think that helps the buds swell and dense. I'm trying to limit what I use to just stuff found at the hardware store. Normally I'd do some other things, like use Liquid Karma. But, my goal was to demonstrate how someone could just go to the hardware store and grow decent plants. (LED lightbulbs, Kellogg Cactus potting mix; MG All-Purpose & Tomato; Pennington Fish Fertilizer & Pure Kelp.). I'm thinking I'll end with MG Tomato, which is a 1-1-1.2 NPK ratio. That will be very N deficient in this cactus mix. That will be like "booster" proprotions of P & K. (Normally, booster would be NPK ratio 1-3-2 to 1-5-3. This cactus potting mix is weird.).