I have a female betta in my 20 long planted tank with 5 whiteclouds and some mystery snails. She has started fixating on one corner of the tank. She swims back and forth, up and down all the time. She will come over and eat but immediately goes back to that corner. Sometimes she has stress stripes and sometimes she has breeding stripes. Her ovipositor is protruding a little and she is a little fat. I put a piece of cardboard in that corner thinking she was stressed by something outside the tank or seeing her reflection. She still does it! Any ideas? Ammonia 0, Nitrites 0, Nitrates 40.
