Just for your curiosity sake, what kind of PH tester I'm using for my fish. I've 6 tester in the house 3 electronic tester, 2 liquid tester and 1 paper. Why the amount of tester? well first I like collecting tester and second there are occasions when I feel the tester isn't supposed to be reading the result it should and I've no way of telling. When you've this amount of tester than my hunched is irrelevant. Marulioides is highly dependable on PH so a good tester is definitely required. In the long run an electronic tester is cheaper and much more convenient especially the reading at 0.00. And I usually play at the borderline of 3.5 - 4Ph which is rather dangerous. So a reliable tester is required. Hand held tester is cheap but needs constant calibration unless you keep them dipped in neutral solution. Liquid tester brand that I've always trust is Sera and Tropical. But do be careful of expired tester in the market. China made litmus paper is hopele...
Fishiology - is a nonscientific study of fish, a branch of Aquarist