I never use runoff in my VEG and all the plants look perfect and in my bloom room I have one row with runoff trays and one row with no runoff and the plants with no runoff look better than the plants with runoff. ¯\_(ツ)_/¯
I understand the idea of balanced nutrition, less risk of buildup etc but honestly pH stability has been better in the pots that get no runoff and running the products armor si, calimagic & maxibloom I have no issues with buildup or lockout, one issue I have is actually pH crash in the plants that are receiving runoff interestingly enough.
I use RO water so maybe that helps contribute to not having scale/salt buildup in the rootzone? again, idk just saying what I see is true.
I rinse, sift and double-buffer my coco with Cal-Mag before I use it and I've never had any cation exchange issues. I use Cal-Mag, GH Flora (micro and bloom only) and Floralicious Plus. This is the first time I've used Floralicious Plus and I believe it has definitely increased yield from my other grows of the same strain. A little bottle goes a long way too.
If salts do build up, they don't seem to harm my plants at all. If I get run-off, it's a dribble here and there but usually I get none as I know how much water to use. I've watered with run-off and without and never had a difference so I just quit with run-off. I also use plain white vinegar to lower pH which many say never to do — I have had zero issues with it.
Towards the end of flower once the buds look ready, I reduce light intensity, lower temperature, lower humidity and use plain water with no run-off until the leaves fade and I chop after a week or two of that. I find if I don't reduce the light intensity and nutrients, I get foxtailing and seems the buds will never finish even though they're dense and heavy. I don't want to risk self-pollenation also.
