your right Zandor the middle is too big for clones...by the way I have found some soft
rubber material 1" thick to use like you do in your cloner, cut them down and trimmed them to fit in holes I drilled with my largest paddle bit...I took a 8 gallon tub and cut 2 5" holes in the top; the round pieces I cut out is where I drilled my 1" holes...the rubber fits perfect...now I filled up the res and put 5" netpots in the lid withairstones attached to the bottom of the netpots...after foiling the round clone holders I set them in the netpots, they fit perfectly, now they are bubbling away and the bottom of the clones stick out in order to take advantage of the oxygen...I think this will work...
I wanted to use a sprinkler, but I haven't found one I can use, yet...later, latewood