Has anyone found a cheap cap to fit the Aquarite cell, for cleaning purposes? I see a cleaning stand sold on line for $30 or $40. I was hoping to get a simple PVC screw-on cap at Home Depot. However, it is an odd size -- its not 1.5 inch or 2 inch. I can't find anything that fits it. Does anyone have a way to plug the cell at one end, so you can fill it with muratic solution for cleaning? I've tried the rubber plugs that I use to close the returns for winter, but they don't fit tight due to some ridges in the mouth of the cell.