Has anyone used one of these in a planted tank? Just wondering as thinking about my next tank and what sort of filtration I want for it. Read the basics about these in a book and thought that they might be useful in a planted tank (or any tank for that matter) given that they seem to be much more efficient biological filters. The main question is about flow rates through these- does it have to be low to stop the sand getting blown into the tank, and so you'd need extra pumps for flow in a planted tank. Any thoughts? Edit: just realised that there is a separate filter section- any chance a mod can move this thread please.