Hi, I've had fish and other animals on and off for a while, but I only really started keeping fish for the past few months. In May, I bought a Molly and a Loach. I later added an Albino Rainbow Shark to the tank. I know that the tank they are currently in is not big enough; luckily, they aren't fully grown. I plan to move them into a new tank soon and I need advice on how to set it up. Currently, their tank has an old over-the-back Aqua-Tech filter and no other accessories. The water has surprisingly stayed pretty clear, but when I use my gravel vacuum, a lot of debris and algae comes up from the gravel. The gravel also gets stuck in the vacuum and the whole effort becomes almost useless. I suppose I need a new filter, and hopefully one that isn't insanely expensive. I've heard about filters that don't require replacement cartridges but I'm not sure how reliable they are. Any recommendations on what filter to get, and what other accessories I need? I really just want a reliable way to keep the tank clean and keep the fish healthy.