I was sick of using little plastic containers to do a water change all the time, so I went out and got a siphon. I have used it before, but in a larger tank. When I used it, it really didn't work, and I was puzzled, until I looked down when I felt water on my foot. It was OVERFLOWING everywhere, so much I jumped and ran to sweep it up. My betta went crazy seeing me run back and forth to clean this. :;smack I learned my lesson now.