1. Make sure you ask plenty of questions when you are buying accessories or fish for your aquarium. The salespeople are there to help you, and should be able to handle any concerns you have when buying items for your aquarium.
2. You should take out any carbon filters in the aquarium when you are medicating your fish. The carbon in the filter will remove the medicine from the water, so it is best to remove it all together.
3. Angelfish are normally very peaceful fish, in times of breeding they can get aggressive. It is a good idea to only keep one pair of mating angelfish in the same aquarium, as more of them can lead to infighting.