Acid snow, Walter white, strawberry biscotti. Trifecta.
Is that ranked in order..
I reread your question and realized I didn't answer it fully. You was asking about the advantages of stacking the Rockwool. One would be 6 cubic inches of additional inches of root ball. Another would be it hard to over water them, if I do I can pick it up an squeeze the water out, for instant air. I could go on and on about the reasons I like rock wool. But the biggest on is adaptability. I don't have to commit any on style of hydro or even soil till I see what's up with my start and what race car I want her to ride in. My small auto is always a race between different styles of dro. Hand watering 5 plus gallon pots of promix. Wicking promix in small pots, dwc. Also made a small flood and drain table for two plants. I do to try to keep my self engaged. The more I'm engaged the better the plants will be..
