This question gets asked regularly and I've answered it at least once in the past week. The best thing to do is to put the pump in a tupperware container that has some holes punched in it. Between the pump and the inside wall of the container you line it with fine filter media. Regarding putting it in a false bottom, unless you're very smart with your false bottom design, it's usually very difficult to remove the pump for servicing without a major disturbance to the terrarium. For this reason I personally never use pumps that are in the false bottom itself.