Been a long time. Due to health issues in the family I haven't been around.
My 12 gallon tank is humming along fine. My 5 gallon OTOH...not so good.
We lost the betta. He just faded a way in a couple days one week; he got weaker and weaker and eventually couldn't swim to the top. At the time we had one oto in with him. A couple weeks ago the Oto got very thin....then suddenly plumped right up again. Then, he got thin again and died.
When we set up the 12 gallon, we lost one Rasbora. Recently we lost one Ramshorn. Other than that, everything we put in it has thrived.
The 5? Everything's croaked, and not really that long either. The most that's been in there is one Dwarf Puffer and a couple Otos, or one Betta and a couple Otos. I change 1 gallon a week, siphoning the substrate. I test the water regularly and don't overfeed.
I've drained the tank, cleaned the decorations and resumed. I left the bio wheel and filter in, and I see a couple small pond snails are still hanging around.
I'm going to try another betta, and some ghost shrimp, and see how that goes. I suspect I should add the shrimp first, then the betta afterward.
Hopefully I have better luck....