I'm so sad right now... I had a Marina i25 internal filter in a 5 gallon tank heated to 79 degrees. It said it was for aquariums up to 6.6 gallons. My first betta, named Harold got sucked in there within two days. My ADF named Walther got sucked up the next day.
I returned the Marina i25 and got a Top Fin 10 Power filter. I stuck the intake tube inside a fake plant, so that the plant is covering the intake tube. Now my new crowntail betta who I only had for 3 days got sucked up. I found him with his tail stuck in the filter. I unplugged it and hes still hanging there right now. I'm too depressed to do anything.. I feel horrible. This is all my fault.
I'm going to put him in the container he came in, fill it with water and bury him.