if you are considering trying to get a pump to return the exact same amount as a straight siphon it will be a dissaster waiting to happen, that is , if you could ever even get it to the point of being workable at all. you will deffinately need an overflow of some sort, to regulate how much water can enter the siphon. also, a siphon break, so that you don't have a spill in the event of a power outage. if you already have an overflow set up, then any of the filters listed would return enough, as long as it was clean, and was performing at it's best.