dwc / bubble questions

here is my setup, it is home made.
i have one 5 inch air stone, and a 185gph water pump with a 1/2 inch hose.

i was wondering, should run the water pump at all until the plants are established? my plan is 15min on 15min off

and also i'm running pure water at the moment, i was planning on starting nutes a week after they sprout, is that to early?

yea you shouldn't run nutes until at least 3 weeks. as far as DWC goes it may be longer. not a bad set up though, congrats

You can use organic nutes at 1/4 strength right after they sprout,...but I would suggest you adapt you're 1/2 tubing down to 1/4 and get some push in type adjustable drippers.....a full 1/2 inch stream of water is too much...you will need to run the drip continuous until the roots reach into the nutrient solution then you can water 15 min. 4 times per day....
hope this helps......