I have a Titan Controls Short Cycle Timer and have found it to be very reliable.
It is a bit hard to calibrate also so I actually used a watch to set it accurately.
But once you set it up it is very reliable and you might not care if it runs for say 14 seconds instead of 15.
With that said since it starts at 5 seconds on you may not want this timer for a high pressure aeroponic grow if you are running very short cycles like 2 or 3 seconds on as some do.
Personally I would use it for HPA because I think those short cycles are overkill anyway.
The timer also has a photocell which is important if you only want to run something days or nights but with any type of aeroponics system you will need to run it 24/7 so make sure it is set that way.
The manufacturer says this about the Titan Controls Short Cycle Timer :
- 5 second to 30 minute ON TIME. 5 second to 60 minute OFF TIME
- Precise short cycle timing of CO2, pumps or fans
- Controls timed equipment during daytime only, nighttime only or both
- Enclosure protects internal components from dust, rust and moisture
- 15 Amps maximum/120 Volts/60 Hz./1/3 HP