Not trying to disagree with anyone , but , I use 2x2x2 rock wool cubes in my aeroponic cloner, I run it 24/7 for months at a time without any cleaning, [I am very careful about what goes in the water]. The cubes I put in water , some have been in water for weeks, never have broken down in any way. They come in sheets that have 10 cubes by 10 cubes [100] and i cut them off as needed. A few of the cubes have developed a green slime onthem and i just washed them off in the kitchen sink with no break down. I believe the green slime comes from the light that hits the water making
it grow. The sprayers hit
on one side of each cube so the roots get both water and air constantly.

The only real trouble i've had with the cubes has been a ph problem that flushing well has taken care of. Plants grow very well in the cloner, so well that i've been thinking of putting the sprayers in my ebb and flo tray.
I know other more informed growers have a different opinion, this is just what i've been doing sucessfully and I don't mean to step on any toes.
I hope this helps
peace
heart
heartsurgerysurviver Reviewed by heartsurgerysurviver on . mental block about rock wool cubes are drving me crazy I took pictures and they didn't come out well enough to show anything. Thanks to notanovice for helping, at least now I know how to do it. I think that I solved my root rot problem and I think it was due to the rock wool deteriorating and contaminating my system. I follow instructions that I have gotten from all the great people who have given me advise. When I soak the cubes in 4.5 ph water for 24 hours, they seem soggy and not easy to work with when either putting in a clone or a seed. Rating: 5