As promised — I fixed everything, dialed it in 🙂 Plants are doing great now, growing fast and looking healthy. You often see people asking: “My runoff pH keeps dropping, what should I do?” I used to recommend increasing potassium, even though at that point it was just a theoretical assumption — I hadn’t actually tested it yet. Well… now I have. And it works. Situation: Input pH is stable around ~5.8, but runoff pH keeps dropping over time (in my case down to 5.2, even 4.7 on one plant). At the same time, EC is either dropping or at least not increasing. I tried light flushing — yes, it helps temporarily, but: Only short-term — next day pH drops again Adds unnecessary stress to the plant (basically suffocating the roots) Solution: Increase potassium. First, I boosted it by about +50%, then added another +30% on top of that. Example: I had ~2 ml per 10L → increased to 4 ml → after 2 days up to 5.5 ml of Canna Mono K. It took about 3 days to stabilize — runoff pH went back up to ~5.7–6.0. If you’re using base nutrients: Just get some Canna Mono K — it’s made exactly for situations like this. Yeah, I know I’m basically mixing my whole solution around it, even though Canna says you can’t build a complete feed with it alone — but in practice, it works for me. Also, side note — now 10L lasts me about 2 days. And that’s it for veg — switched to 12/12 on day 36.