I have a 5 gal tank with three fish (2 tetra and 1 bubblebee catfish), and the gravel hasn't been vacuumed since the initial set-up 4 months ago. It desperately needs it. However, there is a snail infestation and the filter needs changing, so there are a few questions I have before diving in. First of all, the filter media needs changing. The packaging says to change it every 1-2 months (it hasn't been changed since initial set-up either). How accurate is this timeline? Should I change the media before or after vacuuming? I've seen other responses stating that you don't need to change it at all, but simply rinse it in non-chlorinated water. I want to disrupt my poor fish's ecosystem as little as possible. Second of all, we have a pond snail infestation. I've been picking them out as best I can, but those suckers are not easy to get rid of, as you well know. I'm hoping the vacuuming will help, since they'll have less waste to eat, and maybe I can pull loads out as well. (Before you ask, yes, I've been underfeeding my fish in order to combat the snail numbers.) Will the vacuuming rid me of most of the snails? Maybe just the small ones? I'll probably have to clean the plastic tank plants and castle in warm water, without soap, in order to get rid of as many eggs as possible... How do I do that in a way that won't freak my fish out too much, since I don't have a Stress Coat formula? (We're on a tight budget, which is why it's taken me 4 months to get the vacuum and filter media in the first place! It was a Christmas present for my 6yo daughter ... ) Lastly, because there's so much waste among my gravel, I'm concerned about how much water it will take from the tank. I'd like to get it all in one go honestly, but, again, I don't need my fish freaking out. Should I do it in stages? i.e. No more than 25% today, and another 25% tomorrow, and on and on until I'm satisfied with the gravel? Is 50% too much at one time? More? These probably have easy answers, but I would like to know as much as possible before starting. Thanks in advance to anyone able to help a struggling newbie!