Mark is right. I missed that one about pressure side. Brain focused on suction and that was it. Still may work though. I've used a 1.25" poolhose and a homebrew nozzle as a deluge gun for kids or washing the solar cover, hooked together with slip joint PVC like I suggested and very seldom blows apart. The sanding does rough up the surface and it may work. What have you got to lose?
Al