problem that the roots are in the solution for 15 minutes
 

Ron you are the best hydro site on the net. now that i softened you up i have a couple of questions. regarding the 11 plant system i read that for my "tomato" plants i should water 15 on and 15 off. only problem is that the roots are in the solution for 15 minutes as the timers shortest increment is 15 minutes. the bottle fills up in 2 or 3 minutes. all that extra time the roots are submerged. is it ok to leave 15 on 15 off? also any ideas as how to convert the 2 litre to the 1 gallon size. thanks again HAWK

Yes the roots don't need to sit in the water for 15 minutes. That's the reason I use grow rocks so they can sit in water without getting root rot.
That's why I am still waiting for some online member to put together an inexpensive cycle timer that I can sell for them with my gardens.
A 1 gallon safety cap will fit into a 2 1/2 inch tee if you use a 2 1/2 thin wall insert which you may have a hard time finding outside Florida.