I seriously have no idea how but parameters have gone apes***. 15 gal: 45+ hob filter with carbon filter and scrubber [thats what the box had included] GH 180+, KH 180, pH 8.0, NO2 10, NO3 160. Sand substrate, few plants doing, eh. Feeding Fluval color enhancing flakes, just enough to not leave much behind once a day. Using Aqueon ferts once a week. Everything was normal with exception of hard water last week. Thisart I msy be lynched on: 6 pygmy cories, 5 cardinal tetras, 1 golden gourami [until suitable home found], 1 tiger snail, 3 ghost shrimp, 2 zebra danios [the glowlight type but I dont make them glow] and three juvenile mollies. Expert intel requested. How did this happen? The parameters, not the stocking.