LAST WEEK END I ADDED A SECOND 500 GAL STORAGE TANK. HAVING READ THE STICKY BY NOFOSSIL ON STORAGE SYSTEM DESIGN, THIS WAS A PERFECT TIME TO RE-PIPE. WHEN THE BOILER IS OFF AND THERE IS DEMAND, IT SEEMS TO LACK MAJOR FLOW THRU STORAGE. MOST FLOW IS PULLING OUT OF THE BOTTOM OF THE FIRST TANK, THRU THE COLD BOILER, THEN TO THE HOUSE. I'M THINKING OF PUTTING A ZONE VALVE BETWEEN THE TANK AND THE BOILER RETURN. ANY OTHER IDEAS ?