Rochester Minnesota Marine Aquarium Club (RMMAC)
I just replaced my prefilter, 5 micron carbon, 1 micron carbon, RO, & DI (pretty much everything) and I added an inline TDS meter. I am a sucker for toys, I love seeing that my water is 0-1 ppm after leaving the RO and 0 ppm after the DI. My logical excuse is that I can now have a better idea...