1. Cloudy water is normally a sign of overfeeding your aquarium. Judge the right amount of food to place in the aquarium to not leave too much residue due to overfeeding.
2. You should keep some brushes on hand, especially if you are a reef aquarium owner. With your brushes you will be able to clean off any built up grime from inside your aquarium or on the surfaces of your hard corals.
3. Only use medication in your aquarium when you are out of other options. You should use a separate tank to medicate sick fish as some medications can have harmful effects on healthy fish.