I used a recycle timer for 1 min on 5 min off, or 30sec on 3 min off. Seemed to work well for everything from seed to finish.
Ahh excuse me he says hes going for aeroponics. So yes if you are spraying at +60psi of pressure and can generate sub 50micron water droplets then yes 15seconds on and 15mins off. If you are however not using the kind of caliber equipment that can produce a true aeroponic environment then all this is nonsense