Angelfish die easily because of the following problems:
- They are already sick when brought home
- Weak genetics
- They’ve not been appropriately acclimated when introduced to the tank
- Water too hot or too cold
- Water pH too low or too high
- Inadequate filtration system
- Lack of oxygen
- Inadequate swimming space
- Fighting injuries
- Poor feeding
When properly taken care of, angelfish are actually hardy and can even live for ten years or more. To ensure your angelfish live long and healthy lives, provide them with ample swimming space, maintain the ideal water conditions, and give them a healthy diet.
Also, make sure to buy them from reputable breeders and acclimate them properly to the tank.