what type of timer
 

In the 11 plant hydroponic garden, what type of timer is available to create an ebb and flow on a regular basis? The regular timers I have only have an "off" time and "on" time once in a 24 hour cycle. Also, what medium is used for the original starters in the halved plastic 1 liter bottle plant holders? Thank you very much, Bobby

They are hard to find but they are timers out their that have 48 pins that gives you 30 minutes on time and 30 minutes off time for 24 hours. Keep looking. I use nothing but grow rocks in the 2 liter garden.