Couple of questions. I think you may have already addressed them, but I can't find them now : /
How high up do you need to flood the pots? Also, I think you said this, but do you use anything other than the Hydroton? I'm getting ready to buy the parts next week for my table, and just don't want to mess something up.
The overflow fitting is adjustable to flood about 2 inches deep. You can buy extenders that add an additional two inches. Or you can just partially unscrew the pieces of the fitting. You'll understand perfectly what I mean when you see it. I have an additional piece that give me about a 4 inch flood so
I don't use anything but hydroton unless I'm growing from seed, then I start the seed in rockwool plugs and put that in hydroton. For clones I just put the naked roots directly into hydroton. Works for me.
There are so few parts in flood and drain. That's the beauty of it. It's a pump a timer and two trays. Sure things can go wrong, but a kinked tube or a burnt pump is about the extent of worries
For example: I cut 25 Chronic clones yesterday and put them in my aerocloner. This morning they were all wilty. I look inside and the res is dry. There's a rubber plug in the side that the power cord for the pump runs through. If it isn't seated properly (and it wasn't) all the spray the hits it seeps out and it drains in twelve hours. So I fixed it and think the clones will snap back (otherwise I'll take another batch, no big deal). But there's strain on the pump running dry like that too. and it's not a cheap pump that I want to replace. I may seal up that hole and just run the cord through the top instead. This has happened a few times before. I could just be more careful, I suppose, but my point is, shit happens even when you think you have it all figured out.
I really like your setup, I am thinking about doing something similar to this really soon
so, make a list and get moving. Read Stinkbud and Al b Fuct.