The DT17C is a good digital timer with 1 min. resolution for about $25.

I have an aero/hydro hybrid also and I run the pump when the lights are on, ie, 16 hrs/day.

I have experimented with times from 15 min/hr to 24 hrs/day and I can't see that timing makes any difference to the plants I can measure. Turning a pump on and off a lot makes the pump fail sooner.

I grow mostly chiles.

Yeah I tend to agree with you on the timing. I was just addressing Propman's query for a cheap timer with one minute resolution. By the way what sprinkler make/part no. are you guys using? And what kind of spray radius are you getting?

I know the DT17C is a good digital timer with 1 min. resolution for about $25.
but is it true that it can only do 14 on off programs a day and 98 on offs per week. that will not work for 3 min on and 5 min off.

I am using a brass chamion 360* sprinkler head and 8 in riser with a magneteic drive 120gpm pond pump in the center of the rubermaid and the radius is about 18" it hits all 11 roots no problem. and the head is big so it wont clog. there is only one head per rubermaid.

This is what I use for an emitter...it is inexpensive, doesn't plug up readily and has very low pressure drop

Here is a link that might be useful: Low Pressure Drop Emitter

Low Pressure Drop Emitter? will that emiter go 360*? tell me more

Have you guys ever used this pin sprayer in your setup?

http://www.futuregarden.com/cgi-bin/shop/70-1029.html

I don't bother with 360 deg sprayers as all you are trying to do is get nutrient on the roots and this can be done many ways. I tried them and they plugged up and the plants grew the same.

Misting sprayers look very cool, but their function is also to get nutrient on the roots. They plug up and have high pressure drop and the plants grow the same.

Aeroponics puts nutrient solution on the roots which are suspended in the air...this can be done by many kinds of emitters and it doesn't have to be a misting type.

15/15 is fine, as long as you don't have the computer fan blowing air in, during the off time. That's a simple fix, just have the power supply, for the fan, tied in with the timer running the nutrient pump, that way, you are getting fresh air in, during the spraying cycle, no risk of drying out then, and it's off during the off cycle, so drying out is minimized.

the low pressure drop emiter link does not work