thanks for the suggestion, the reason why I asked about the filter was because on the filter packaging, it recommended to reduce the water flow during eating, so that way, it allows the proper growth of the beneficial bacteria, so I just wonder if i buy a filter that's too powerful, it may become overkill?
I think I have a 'special" turtle, I had her for 5 years but she's still as tiny

- about 3.5 inches, please don't get me wrong, I 'used' to feed her everyday and not till about 3 weeks ago, I started to feeed her every other day since i was told that it's better that way for a grown turtle. She was once diagnosed having MBD, but she's been doing good, I saw her shedding her skin about two times in pass 3 month now. Since I have a slow-growing turtle, I decided to go for 20L for now(she looks tiny in it), when she grow bigger, I'll upgrade to a better one

I'll be getting her a brand new filter soon, and please, more suggestions are always welcome.
Is AquaClear a good brand?
