I've had a 5 gallon since December. The parameters have always been really good, and I do a 25% water change every week.
I just checked the parameters and I'm having at Nitrite spike. Any ideas of what might be causing it?
Also, I have a Betta in the tank as a showcase fish and he's been acting strangly. He's been sitting on the leaves (it's a live plant tank) with his nose down. Any advice?