Overwatering hempy bucket

is it possible to over water a 75% perlite 25% verm hempy?

There's no such thing as over watering just under oxygenating, it's possible to "over water" in just about any medium/system, follow the hempy rules and you will be golden, hands down easiest hydroponics system there is and a ton of info out there about making/maintaining them.

You should have a water run off hole just above your perlite. If done properly you will never have more water in ther then that hole. Unless something is blocking it from draining.