I have to improve my AG cooling methods due to the fact our tap water is over 80. I have been running tap water through a pre-chiller placed in a cooler of ice water then over to the immersion chiller until it gets down to about 110 (10-15 mins). I'm not sure the pre-chiller is very effective. I then switch to a battery powered sump pump and recirculate the ice water through the IC but the pump is pretty weak so the entire cooling process takes about 45 minutes to get to 65 degrees. I wanted to get a sump pump to use in place of this battery powered thing I have but they seem to be 1000+ GPH which seems like way too much for what I need. Does anyone have a pump recommendation?? Thanks!