On my system (low pressure sprayer), I was running something like 30 min. on, 45-60 min off from about 6 am to 8 pm, then on for 30 min. one time at about 2am. This was a function of available timer settings. Anyway, It's always worked well for me.
I have read on other threads here, that cycling a pump that much (1on/5off) may dramatically shorten its life, so do some research before committing to that kind of frequency.

yeah, thats what I'm worried about (pump life).

You can use a short misting cycle for low pressure aero and still have the pump running 24/7 :)
Add a tee to the pump outlet, put a normally open solenoid on one side of the tee (leading back to the res) and the line to your sprayers on the other side of the tee. Connect the cycle timer to the n/o solenoid.
When the timer is "off" the solenoid will be open, your sprayer line represents a much high resistance to flow so the pump fires straight into the res (aerating the nutes at the same time).
When the timer is "on", the solenoid is closed and the line to your sprayers will pressurize ;)
You could use a cheaper normally closed solenoid but as it would be "on" a lot more than "off" its life expectancy would be a lot less.

Any examples of said solenoid valves? I can't seem to find any.

you can find solenoids at Lowe's in the automatic lawn watering area.
Finding a DC timer to run them may take a little more effort.
Also not sure if they're normally on or off.

Hi Grizzman
You wouldn`t need a dc timer. Use a standard cycle timer to fire up the mains side of the low voltage adapter/power supply thats feeding the solenoid. I`m the other side of the pond so i can`t help with a supplier but you shouldn`t have any trouble locating a n/o solenoid online.

I use the 12vdc pushfit type (#1175BC)listed in this pdf,

http://www.solenoidvalvesuk.com/catalogue/filecatalog/Page99.pdf

The optional N/O coil is more expensive.I know it doesn`t help you much but at least you`ll have a better idea what to look for.

Hex,

Any chance you could post a picture of your setup and how this valve is integrated? I'm having trouble wrapping my head around it.

Hi Evil
I use high pressure aero so i don`t use a n/open solenoid or need a low pressure pump running 24/7 but the solenoid layout is very simple.
Fit a tee to your pump outlet.
Connect a pipe from the tee to your sprayers.
Connect another pipe from the tee to the inlet of the normally open solenoid. Note: the solenoid needs to be located outside the reservoir :)
Connect a pipe from the outlet of the solenoid and feed that back to the reservoir.

When the solenoid is off, the valve is open. The water flow from the pump takes the path of least resistance through the open solenoid and back into the res.
The sprayer path will present a much higher resistance to flow.

When the solenoid is on, the valve is closed which effectively blocks the easy path back to the reservoir so the water has no exit point except the sprayer path.

Solenoid Off: Pump > Tee > Solenoid > reservoir.
Solenoid ON: Pump > Tee > Sprayers.