A filtered, cycled 5 gallon should be fine with once a week 50% water change..If it isn't cycled you might want to up it to two 50%'s.
The list of things I use to clean my 5 gallon tank :
- Gravel vac siphon
- 5 gallon bucket
- aquarium sponge or algae scraper ( I only use this if the glass is looking dirty or spotty)
- water jugs
- water conditioner
I first unplug everything, then I fill up my water jugs with water the same temperature as the tank..using a thermometer helps.. I then add the water conditioner to the jugs.. I clean the inside of the glass if it needs it...then I start the siphon and clean the gravel with it. When I refill the tank I make sure to pour it into my hand or use the betta cup my betta came in so it doesn't create a strong current..Once everything is filled back up I plug everything back in and I water my herb garden.