help with pump times

Hey I just built my first aero setup ever. houses 21 plants and I expect to fill all 21. I was looking for pump times every where even the stickys and no help. SO How long and how often should i time my pump to spray or should it be running all day? Thanks much in advance and happy growin to all!

There are several time schedules you could use . 1 minute on 4 off , 3 on 5 off ,15 on 30 off .

Depending on the the size pump you are using 24 hours on will run your res temp up . unless you are running a chiller .

http://www.plantlightinghydroponics.com/cap-nft2e-3minute-on-5minutes-off-preset-recycle-timer-p-1726.html