I did the CH test yesterday and at about the point where I expected the color to turn, instead I noticed little blobs of pink swirling around. I did it again, same result. Instead of something like 240, it turned at 320, but I have not been adding calcium via cal-hypo for several weeks, or hardly ever, maybe once. Tried again today but got the same result.
Any chance the reagents are temp sensitive? It is about 99 degrees out there right now. Both times I was doing test outside, not in the house like I typically do. The reagents are stored in the house, so should not have warmed up so much.
Maybe I was hurrying because of the mosquitoes. I was trying to wait long enough between drops though sometimes they do tend to drip out on their own schedule. Could wait time be it?
Otherwise, could calcium rise as rocks in the waterfall wear down? I get a lot of sand from the waterfall and I suspect that adding acid to lower TA could be increasing that wear. Would acid leach calcium from sandstone?