1. When breeding angelfish, it is normal for the first spawn to suffer heavy losses and not make it all the way to the hatching phase. You should have the proper equipment before you start to breed angelfish.
2. It is not a good idea to wash your filter media with regular tap water. The tap water can kill the beneficial bacteria that is built up in the filter. Use distilled water to clean out your filter and its components.
3. Make sure to keep a log on hand to update any changes in the aquarium. This will help you keep track of changes in your aquarium much more easily. Keep your aquarium log in a place where you won't forget it.