I'm flowering plants in rockwool/rockwool slabs at the moment and couldn't be happier. You can dump gallons of water in the rockwool and it will drain to a nice level of moisture, my plants have never once looked like some of these people's using soil. I also water every day and saturate the rockwool a lot since I use drain to waste. (~20% leeched)

I don't use ebb and flow but I'm pretty certain that, if you aren't dealing with seedlings it doesn't really matter how that cube is once your plants have a lot of root mass into the hydroton. That 1 inch cube is nothing more than a tiny spec your plant grows through at that point.

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In Heaven, all the interesting people are missing. - Nietzsche