I have a single Molly and a neon tetra living in my 10 gallon tank. One Molly died and my other 5 tetras died. I have test strips and nitrite and nitrate are high. The kit says to do a water change so did 30% one but there's no change. I would buy more neons but I don't want to risk anymore dying. I noticed i definitely added fish waaay before a proper cycle. I added them the day after i set up my tank. Anyway, what should i do to lower nitrite and nitrate??? I'm lost and if i can't figure out what to do I'll have to give up on fish for their own good.