How should I set this timer??

I built an ez cloner, and got this timer http://www.ebay.com/itm/Repeat-Cycle-Timer-40min-Hydroponic-Aeroponic-EZcloner-/290913569086?pt=US_Hydroponics&hash=item43bbccc93e

how should i set it?!
I know a lot of people set it to go 24/7, but i bought this to reduce electricity costs.
i hear 1 min on 5 min off is the standard
but this timer does 50 second pins, with 48 pins, for a total of a 40 minute cycle
thanks!

until they have roots i would run it 24/7. I doubt you will notice an increase or decrease in the bill from running a small pump like we use on those. I ran a 1000w lamp, 400gal pump, a/c, demumid occasionally. My bill went up maybe 50-75 a month in "mild" weather. When i tried in middle of summer and ac was running 24/7 full blast it was more like 150 a month.

1 MIN on 10 MIN off