The areator I built is portable so I can use it when fishing. It uses a 350 gph bilge pump, a 4" floor drain, upside down, some u-cut air filter material, a short section of 2" pipe into a 90 deg elbow to 3/4" pipe with a small hole drilled in for an air hose (which I cut the end at an approx. 45Deg. angle facing away from the pump), then a 3/4" to 3/4" elbow. It works very well keeping fish alive for days. I haven't used it more than a week at a stretch yet, as I only have gotten 3 dozen that usually last for a couple trips. When I set up my big tank this winter I am looking at using a fountain pump to circulate the water through a whole house filter then into a 5 gallon bucket filter and then dropping back into the tank...