Okay, so my betta Johnny who used to be so happy suddenly died. I had thought that he killed himself because I found him under his decorative bridge, and I thought he got stuck and drowned...but strangely when I pulled the bridge off, I saw this HUGE black dot on poor Johnny's lung. It looked like a human mole! It was disgusting, but what is it?? I didn't get to take a picture of it. Anyways, after Johnny had passed my sister and I went out to Petsmart to get a new betta. We found the cutest little guy. He was a baby crowntail. We called him Little Joey Caesar (or Joeus Caesar). We took him home, and Johnny's old tank was a big filtered 3.5 gallon tank with awesome lights. My sister and I scrubbed it and cleaned it perfectly with no soap, we put warm tap water in a bottle, put conditioner in it and let it sit for a long time. Then we put it in the tank and let it sit for a while. We put Little Joey in the tank and watched him carefully. He immediately loved it, and he was comfortable. But, we noticed that Little Joey Caesar became VERY lazy, he slept ALL THE TIME!! I'm not joking! He wasn't eating, and he was acting strangely. Then, my sisters and I went to my living room and watched a movie for a couple of hours. I went to go check on Joey right after the movie was over, and I found him belly up by his decorative plant. He had a little black belly, too!! It was weird! The tank is perfectly fine, and I checked it for any little weird thing, and it was perfect! I scrubbed it even harder and cleaned it even more, and I made the water better. I put Mr. Jingles in there, and he's loving it! Johnny had stayed in that tank for two months, then he passed. For Little Joey, it was two days. Mr. Jingles is very healthy. So..... what the heck?? Thanks for reading, and any advice or tips or comments are needed!!