The Federation of British Aquatic Societies (FBAS) estimates that over-feeding and water fouling kill more fish than any other action.
This help guide contains tips and advice for troubleshooting the most common issues with fish kept in an aquarium or an outdoor pond.
Some of the frequent mistakes made by beginner aquarists include:
Aquarium keeping as a hobby doesn't need to be a big commitment for it to be fun and rewarding. Not to mention the educational aspect of taking care of fish and how it can also benefit your mental well-being.
However, it takes a while for absolute beginners to get to grips with the fundamentals. Plus, when calamity strikes, you'll need a handy resource to help you troubleshoot the issue and find the best solution.
Pro Tip: Another help guide simplifies the "legal duty of care for keeping fish' according to the Animal Welfare Act 2006 (England and Wales) and the Animal Health and Welfare (Scotland) 2006.
This section lists the most common fish diseases that occur more often than others. Each link takes you to a page with more information about the causes behind the issues and different ways to solve them.
Pro Tip: The main fish keeping hobby section contains more information about setting up a simple home aquarium and why it doesn't need to be expensive.