Finding a Timer

I need to find a timer that will run seconds to minutes
at 5sec on, 5min off, 24/7

this is for my Aeroponic system I'm working on
its the last thing I need for it to work
any input would be greatly appreciated

I own a Sentinel MDT-1 timer and wouldn't trade it for anything else. It does down to the second but might be alittle more than you are looking for as it controls lights as well as a lights out receptical for heater,dehumidfier, ect. With all the bells and whistles it is actually a good buy at 150$
Here is a link but you can find them cheaper around the price I got mine at with shipping included.
http://www.growwurks.com/sentinel-mdt-1-master-digital-timer.aspx
They also have this model which is just a digital timer down to the second also...
http://www.growwurks.com/sentinel-drt-1-digital-recycling-timer.aspx

Hope it helps you out..I"m doing a low pressure aero system if you want to check the link in my sig...

Awesome actually I need it to control an ultrasonic fog/humidifier that needs to run 24/7 5sec to 5min.
thank you for posting about this you have no idea how helpful this has been man if I could I'd pass you a blunt, Low pressure is lookin nice, Once I find a timer I have that ultrasonic humidifier set up to grow with 2" pots. should be done within the week now that I found a timer to run it.