Gorilla Zkittlez in mineral wool

Hello, my dear friends! It’s time for the Gorilla Zkittlez from Barney’s Farm. I became a fan of this seed company after a solid Blueberry OG. The setup: Substrate: Mineral wool cube + Uni-Slab from Grodan. Watering: Drip with automatic drain for waste removal system Nutrients: Terra Aquatica TriPart, Root Booster for initial stage, Fulvic, CalMag, Bloom Booster (maybe), Ripen, FlashClean Feeding till Day 4: 240 ppm, pH 5.5 2 waterings per 60 ml a day Day 5: 350 ppm, pH 5.5 2 waterings per 60 ml a day It seems, the solution is too low ppm. Will increase a bit. I think she’s stunted due to low ppm or overwatering:( brown tips and edges. Upd: Put dripping sticks underneath the cube for a night to dry the wool a bit. Raised ppm to 410. Removed the sticks and put the cube back on the surface because the first root coming out of the wool dried out immediately. Day6: Raising ppm and light intensity (till 15 DLI) was a bad idea, the leaves were pointing upwards at 45 degrees angle in the morning. Dimmed light back to 12 DLI, diluted solution till 330 ppm. Leaves got back to normal state in few hours. The tissue right near the block helps drainage. Increased amount of solution per watering from 60 to 100 ml two times a day to speed up solution exchange in the wool. Need it a bit lower. Runoff 350 ppm, pH 6.4 VPD 1.3 day / 0.8 night Day7: She became a bit bigger overnight. New fresh roots coming out of the wool. The second pair of leaves is developing. I will not exceed the 350 ppm point until runoff will be the same. Keeping solution pH at 5.5. Runoff 375 ppm is higher than yesterday possibly due to salt residue on the tissue. Will check next time with a clean tissue. Overall this week was very exciting. This is my first experience with mineral wool in 15 years or so. It was tricky to prepare, a lot of adjustments needed. Im currently using magnetic stirrer to mix solution 24/7. It prevents layering of particular components overnight. It was difficult to decide which ppm to start with. Although a lot of sources provide such info, I can’t trust all of them. Should just get back to Jorge’s Bible and reread “Hydroponics” chapter. Probably I would avoid the issue on day 6. What happened on Day 6? As far as I remember, I changed solution on Day 3, and noticed slow growth on Day 4. For solution I used 1 ml/l CalMag this time, which made up to 500 ppm in combination with a normal NPK dosage. Then I diluted till 350 ppm, but NPK part was just almost the same as Day 3. So basically I corrupted K/Ca/Mg ratio which should ideally be 4:2:1 (article: Balancing the Nutrient Equation - Cannabis Business Times). Additionally, I was struggling with pH balancing in low ppm solution. When I made it 5.5, a few hours later it went 6.0, and I had to add pH-down again. And so on. I think at some point she could also receive pH 6.0 on Day 3. From now on, I adjust pH very slowly by adding pH-down till pH 5.2, then few drops of pH-up till 5.7, and again pH-down till 5.5. Surprisingly, pH stayed the same during the whole night after that trick. No more drifting. I really hope it will help me in future. I realised it’s a bad idea to pH-balance solution right before watering. It should rest for at least few hours to stabilise. Only after that the final adjustment with pH-down and -up needed. I noticed that my pH meter shows readings very slowly changing in 6.0-5.0 range. That happens exactly when the solution is not stable yet. When pH is stable, the meter gives the proper reading instantly.