Those are the exact pots I am using Bob! How high do you flood up the side of yours? I flood for 15min at a time and it only reaches about 2" up. Does the water touch the rockwool inside (if you use it)? I think I planted my rockwool cube to high in the pot and when I flood the water doesn't get high enough to water the roots properly. I don't think the roots have had a chance to grow far enough down in the pot. I notice that some of your plants are only using the bottom half of the pot. Do you pull them out and add more hydroton when they get bigger?
I flood for 10 minutes on every even hour (12, 2, 4, etc.) - the water level gets to about 4-5" up the side of the netpot, and would get higher save for my overflow valve.
I don't use rockwool, just go right from my DIY bubble cloner straight into the hydroton.
Not planning on adding anymore hydroton to any of the pots - they're too big as they are, honestly - going with 64 6" square pots for my next run.
Also, there's an interesting contrast in my journal (last post) showing the difference between my clone's roots which have reached the flood zone and those that need some more time - kinda interesting, you should check it out.