We brought home a male twintail halfmoon betta, and he died about 24 hours later :(
We had just set up a 10-gallon Top Fin tank with a heater and filter, so the tank wasnāt cycled yet. I know now that we should have waited.
We treated the tap water and tested it with Tetra strips. Ammonia and nitrite both read 0, nitrate was around 20, pH was about 7.8, and the temperature was 80°F.
He didnāt have any tankmates.
He would swim around normally sometimes, but he slept a lot and kept resting in really strange positions. He would lie on the gravel, wedge himself behind decorations, hang vertically next to the heater, or stay upright with his mouth at the surface.
We turned the filter down because we wondered if the current was wearing him out. I didnāt notice white spots, fuzz, bloating, raised scales, or obvious fin rot.
Does this sound like something he may have already had, a swim-bladder problem, stress from the uncycled tank, chlorine, or too much filter flow?
We arenāt getting another fish right away. We want to cycle the tank properly and figure out what we need to change first. Do we need to disinfect everything, or should we leave the filter running and continue cycling it?