Good morning OFC. I
I'm scratching my head on pH drops. Every day my reservoirs drop a little. I have an automatic float keeping a constant level. Tap water ppm is 100, soft naturally. Tap water pH is 7 or higher. The natural progression is as transportation takes up water, a small amount of higher pH water would be added. Contrary what should be happening, pH drops a little. When pH is below 5.8, I add a little acid, (GHs pH Up) and bring up the pH back up to 5.8. I don't want to shock the plants and am adding pH Up cautiously. My Raspberry Coughs absolutely love the mix. My AK48s have what looks like multiple nutrient issues. My guess is pH is too low for it. In a few weeks, it's done. Except for leaf color on old growth, it is blooming well so I'm scratching my head on that, too. I'm switching to different genetics too so I have another reason to trek through and move on to my next crop. One last thought is that chlorine in tap water is added too fast, overpowering the natural evaporating out of gasses. I am extremely well aerated, that should make the evaporating out of chlorine gasses rapid.
I recently increased the feed ppm. The only thing I can think of is that there is a buffered low pH in the feed that has so far overpowered the acid. I'm using GH trio with CalMagic maintaining 900ish ppm. My lights are limited still for economics. I got carried away on growing, anticipating more die offs. I ended up with too many plants doing fairly well and am too soft on culling out perfectly good plants. In the next six weeks, they will be good to harvest according to the charts.
In related news, I was checking trichrome color and saw one tiny little caterpillar type worm on the upper part of an AK. I ordered a phone plug in microscope to look more thoroughly. It was only one, and I can't find any more. Maybe bugs are hurting it and they are too small to see. 45x is where I found the one. I grow in water and lava rocks so far. I may be switching to aero spray to get rid of pest harboring issues. I'm treating the area with pyrethium and another insecticide that was premixed together. I don't want it on the plants. The insecticide stuff was left over from summer treating camping clothes for ticks. It's not meant for plants, so I'm doubly leary of the stuff on food stuff. If I can find another worm, I'll test an insecticide on it to see what works. I did a search and it looks somewhat like a rootworm but shaped wrong, and the roots look fantastic. If my camera could capture better, I would post something. I will harvest what I can, clean up the space and start over. The harvest will be big. I'm making too big a deal over one bug, but don't want it to get out of hand. My other closet is clean, BTW.