The planted tanks are 15g and 30g, but my not planted 80-90g got the same result. I don't think they are expired, and they showed the same results right after I got them too. Maybe I got damaged package or something? I looked up my city's water distributor's site and it shows these parameters: GH 1.64 mmol/l , ph 7.4 , magnesium 6.9 mg/l , calcium 54.6 mg/l , and sadly nitrates 12.2 mg/l . And it says it's "moderatelly hard" (1.5 - 2.25 mmol/l ) (the scale goes like this - very soft, soft, moderatelly hard, pretty hard, hard, very hard and so on). I will try calling them about it, whether it really shows precisely what everyone's water in the city is or whether it can vary a lot.
I will post a picture of my rabbit snail's shell, as I thought few months back that I have too soft water for snails (before the test strips, I bought them because of it) - their shells look horrible. I feed them food high in calcium every week.
Do I need all 3 test kits or is gh and kh enough? Thank you all for the help!