I have my pump turn on for 4 minutes every hour. just long enough to completely fill the table to the right height, then slowly drain back out for another 4 minutes. no watering at night. I'm using 50lb of fish tank stone for my first grow. it's been working great. I could probably take it down to every 2 hours, but why try fixing something that's not broke?
I have a second set of plants on about week 2. I have a drip system ready for them, but I'm watering once every 2 days while they're young. I get the earth plugs damp then wait for them to dry before watering again. I don't water the plugs directly, or they get to wet. I pour water around the outside of them in the fish tank stone. this gives them the right amount of water. also, for now, just plain tab water until they get bigger. maybe in another week or 2 I'll switch to the automatic drip system with 1/4 strength nutes.