Electric waterpump and alt only, I need suggestions.

Okay guys I just got around to installing my electric water pump, and I have some questions. I am only running an alternator, and I am using the March performance alternator bracket instead of the stock one. Well I need to keep the belt off the waterpump. Anyone running an electric water pump and alt only let me know how you solved this. I know I need to put an idler pulley somewhere but I need some ideas of where. Thanks.