I finally got a tds meter the water going in to my ro is 201ppm the water coming out is 1ppm. Good? my question is i get this brown kinda spider web looking stuff on my glass and on my rock. its not thick and takes a few days to be visible. But its annoying and if i let it go for 3-4 days i start getting little clear bubbles. DOes this sound familiar to anyone? can you identify?