If you intend to build your own water feature and you've never built a terrarium before, I would advise you to either not go ahead with a water pump or to get one of those premolded water falls with a built in pump, in order to save some heartache. I know no first time terrarium builder who was satisfied with the behavior of their water feature/pump. If you do intend to go ahead with it, Zoo med make a pump series that should do the job. I think they are classified by numbers, like 404 or 505.