I recently built my own ebb and flow system 10 5 gallon buckets. looking at timers at my local grow store i soon realized that this was going to be a very expensive component. Off to the local home depot. apon explaining my requirements in a timer I was told that they didnt sell anything that accurate. So i purchased a timer that had 20 on off setting the kick being that the min amount of time on was 15 mins. a huge problem considering i needed one pump on for 4 mins and the other 3. my rationale was to run my intake pump dry ( a submersible septic tank pump) and save me a few bucks . low and behold i get the thing home and find out that the min amount of time on is accurate to the minute regardless of what the package said. Here is a 12 dollar digital timer with the same specifications as the cap cycle timer my local grow shop was selling for 90 bucks


You can find them at home depo
brand name Intermatic digital lamp timer model number DT300CH

The above model is rated at 500 watts there is a 20 dollar version thats rated for 1000 watts but i cant vouch that it is as accurate.