15 minute timer for Kalk reactor?

[wojo]

currently i have the mechanical timers (from HD) but i think they are 30 minutes minium. i need 15 minute timer for my kalk reactor.

is that what usually folks do? according to Geo's manual they suggest 4 times a day, 15 minutes each time.

thoughts?

[customcolor]

i have a few 15 min timers and i got them from big lots. they have push tabs. every tab is 15 min

[wojo]

i have this, it says 30 minute increments :(

http://www.homedepot.com/prel80/HDUS/EN_US/diy_main/pg_diy.jsp?CNTTYPE=PROD_META&CNTKEY=misc%2FsearchResults.jsp&N=2984&keyword=timer

[wojo]

what would you guys recommend for my setup, how often and for how long?