Ebb and Flow flood times?

Hi all.
I always thought you flood for 15/30 min every 3-4 hours when lights are on. I was reading a post and hereâ??s what it said.
(((Hydroton rocks in net pots requires frequent flood cycles. This medium does not hold as much moisture as the above mentioned mediums. The pump can be set to either 15 min on/15 min off, 15 min on/30 min off or 15 min on/45 min off ))).
What do you experienced E/F guys think about this? I have Blueberries in Hydroton, 6â?� pots under a scrog, 600w HPS. Iâ??m going to start 12/12 today. Also, is it ok for the roots to come out of the pots? Should I put Hydroton rocks in the bottom of the tray?

(The more I read, the more I donâ??t know)

Thanks for any input you can give.

I'd read you flood 4 times for 15 min during each light cycle, But that is just what I read. I plan to do Ebb&flow in the future but using soil my first couple grows.

As for roots coming out of the net pot. That is normal. Only issue you really need to watch for is the roots clogging the pipe. I wouldn't put any hydroton down there though. If they are really long and are close to clogging the pipe. (I've read somewhere) You could trim the roots. I'd wait for advise from someone who's done that though. :thumbsup:

flooding 4 or 5 times for 15 mins each during lights on is what we do. as for the other question how about a pic of the setup so we can see exactly what you mean.