I discovered that my male
betta's tank water was freezing cold (confession: he lived in a small tank with no filter or heater

) so I had to do something about it. He was very lethargic. My sucky
LFS was out of 10 gallon dividers which makes me happy now because I didn't waste $12 on it. Instead I found the
DIY way and made my own for much cheaper.
Neon tetras have been in there for a week and seem to be doing fine. Water parameters tested fine so I added my betta - he's on the right side of the tank. Unfortunately I couldn't get any good pics of him, he's kinda old and dark colored.
