Recently got '98 221. In using aerator (and I properly put in the aerator pipe) when I run boat to a fishing spot the aerator overflows. When I put in live bait I fill the container with enough water so the it goes into the pipe and circulates yet it over flows. Also I am losing bait as some of the bait fish get sucked into the pipe. Is there a filter I should be using .... do I need to shut off valve in the hull?