I am wondering if anyone out there has had any experience with orthophosphate in their brewing water and have had any luck removing it. If you're not familiar (as I wasn't until my boiler stopped working) orthophosphate is what city water authorities put in the water to prevent the leaching of lead from old pipes. This is great except for the fact that it precipitates out upon heating and ends up scalling the inside of boilers and fermenters. I have the boiler situation under control, but this stuff is staining the inside of my fermenters and the only way I can remove it is to circulate PBW for about 4 hours. I know that a water softener will take care of it, but assuming that is not a viable option, in the short term anyway, is there something that I can add to my mash and sparge water to keep this stuff from staining my tanks?
Any advice, as always, is greatly appreciated..

Cheers,
Pete