I have a Fluval 405 that I got a few years ago for free. I've been happy with it. I like the set up for media, with the removable boxes. I'd say that the only issue that I have each time I go to clean it, is that the top is difficult for me to remove. I eventually get it open, but I can't tell you how many bad words it takes before it finally opens, I lost count. I wish that they used standard tubing, and I'm too lazy to convert mine, just because they're a pain to clean, and I'd like to install a DIY spray bar. I had my own spray bar on there, but, eventually, it leaked and flooded my floor (the connection). I bought some standard tubing and plan to do something about the to add my spray bar again. It's on my to do list.