Ebb and flow (EnF) can easily be automated. Depending on the complexity of the timer, just make sure you have an overflow pipe that dumps back into your reservoir and you don't have to worry about overfilling your tray. Another option would be a drip system. basically apply water pressure to the line, let it run a spell (to saturate the medium) then cut it off until next time they need watering.
As for your DWC question, I'm not sure there are plants that won't respond well to it. the concept of plants liking there "feet wet" or not derives from soil growing and is basically an issue to oxygen. Since you're aerating a DWC system, that consideration is taken out of the equation. Now I could be wrong about that, but that is my understanding. But then, I've only grown a limited number of plants in DWC and ficus is not one of them.

emcy,

have you considered passive hydro? i've seen Ficus benjaminas thriving in Hydroton with a non-circulated nutrient solution in the bottom of the pot. i have almost all of my houseplants set up this way. when we leave for a two week trip, i just set my grow pot into a larger reservoir pot. if the plants need to go longer, i have a neighbor come in and refill the pot "up to the line" which is a piece of painter's blue tape with a black mark on it. a fifth grader could do this.

if you want more info on this method, check out the link below, or search on semi-hydro. First Ray's website has a bunch of info on this method as well.

the nice thing about passive, especially for trips is that you don't need to be concerned with power outages, equipment failure, etc.

cheers,

nancy

Here is a link that might be useful: Houseplant Hydroculture

"Passive hydro" isn't a a real hydroponic system/term. It's just a slang term for either a Wick, and sometimes Water Culture system, or combination of both systems. In which no maniacal means were used to keep roots moist or aerated.

Most Water culture systems use a air pump to keep the water and roots aerated. Witch means most water culture systems use a mechanical means to aerate the water/roots. Thus eliminating those from being included in the sub-definition (Passive hydroponics).