Can CO2 titration drops go bad?
I used these 10 month old drops to figure out the CO2 concentration and found it to be about 100 ppm...
ph - ~8.0
kh - ~6.7
gh - ~12.4
I was using diy CO2 for a day or two but I took it out a couple days ago because of these readings. Can this reading be correct or is it the drops?