Hi Hurdicuss,
Thanks for the kind words, very much appreciated.
my experience with CaCo3 is that it gets deposited on things with heat - so pumps and heaters for the most pasrt. I have not experienced and build up in the pipes, but I do see bio-fouling. Having said that, I dont perceive a problem if a large diameter pipe is utilized.
Its a good question, thanks for making me think.
Paul.