I have a home made hydro set up about how long a day would i have to keep the pump on ?

It really depends on what kind of hydro set-up you built.

A drip system should be on while your lights are on & off when dark.

A flood & drain system should run ten minutes every 2 hours while lights are on, off when dark.

Aeroponics systems are a bit more tricky & not suggested for beginners. But I believe the ratio is going to be 1 minute on every 10 minutes while your lights are on.

Hello To You,

I learned bunches of helpful knowledge about hydroponics at this link: http://forums.gardenweb.com/forums/hydro/

I believe you will be impressed at what else you can learn at the main site; lighting, nutrients, etc.

http://forums.gardenweb.com/forums/

Have fun, and Happy Holidays!

all day long and when u finally are done growing ur weed hydro is like the best sh1t out there i love it