Water Blaster, sorry, its a return pump, heh. Also, have to call BS on the vinegar thing. I mean, vinegar is a weak acid at best and most of us use food grade vinegar which is diluted to boot. Add that to the fact that most of make another solution by adding RO/DI and what you've got is a solution that will dissolve some organics and soft minerals (calcium). Rubber could break down, but plastic won't even blink at vinegar.