Hi TreviFountain, and welcome to the world of AP
Depends on the system you build, i.e. if pumping to GB's or Pumping to FT. Syphoning can be automated using a bell syphon and no power, timers or anything involved and is generally used when gravity feeding GB's or un-timed pumping to GB's.
Pumps generally run full time and yes it usually takes loner to fill than it does to drain but that is required to allow the plant roots to take up nutrients. Some people prefer to run constant flood so it never drains, just overflows.
Timers on pumps are usually used when running drain instead of syphoning, i.e. pump to fill the GB and may remain full for a while then pump turn off while it drains away.
The draining process draws oxygen down into the root zone and probably has other benefits with worms and breaking down of organic matter. But as some people use constant flood i guess it is not required.
My personal opinion is if it is leafy greens then constant flood is best, but if it is deep rooted then flood and drain. All my GB's are on Flood & Drain vie bell syphons, and i am about ready to commission my DWC (grown in water only) and soon my Grow Towers (which never flood).
Hope this helps.
