Shawn, not sure as to what your trying to do. If you are trying to plumb two tanks together, then tank connectors might be what your looking for. On my recirculating system I am running a 4 inch pipe between tanks that hold 150 gallons each. Make sure a 2 inch pipe is large enough for your return water, if not your front tank will over flow and you will lose all your water. Most hardware stores don't have everything I need plumbing wise. A  landscape and irrigation equipment supplier will carry larger fittings, pipe, and tank connectors. Hope that helps, Ron