Does anyone have any experiance with these filters? I've noticed that you can get a 900lph filter for just Â£50 and it seems an absolute bargain to me. Does anyone have any experiance with them at all? I'm thinking that I could get a pair to replace the eheim on my 2 foot and a smaller model to replace the eden on my cube. Â£80 for 2 filters inc media is a bargain to be had.