None of the stones work to good for me at this point with out changing them out every two weeks and giving them a CLR bath with a good rinse. I have taken the stones off in my one set up and just put the tubes right in to the water. I do not suggest that but it has worked for now. I am looking into tube bubbler's and working on making my own. I have really learned BIG time that Oxygenation is very very important and looking how to over come the problem in the future. Like I said, I am looking more into
aeroponics at this point and to try that.
FYI: things are growing great in coco coir right now, wow I love it.