Overfeeding is the number one cause of fish loss, and it’s not hard to see why. It is easy to forget how small our pet fish really are, and the fact that their appetites are not the same as ours. Also, because feeding our fish is the main way we interact with them, they certainly come to expect at least a little sprinkle of food each time we approach their tank—and it’s hard sometimes not to give in. However, hungry as they may seem to be, it is important to remember that overfeeding your fish can have serious consequences.

Contrary to popular belief, most fish who die of overfeeding do not actually suffer from any sort of gastrointestinal problem. In fact, the major issue is unrelated to the actual over-ingestion of food. Rather, problems occur when excess food is left uneaten and accumulates as waste in the aquarium. The products of decomposed fish food can be extremely toxic to fish and can also indirectly affect them by wreaking havoc in their aquarium environment. Common signs of overfeeding are easily observable in any fish tank; cloudy water, algae growth, mold/fungi, and clogged filters are some of the most obvious indicators.

Whether you are a new fish owner, or a long time fish lover who has noticed any of the above signs in your aquarium, there are some simple steps you can take to ensure that your fish are receiving an appropriate and safe amount of food.

A good first step is to arrange a feeding schedule. Fish owners who only feed their pets every other day are often surprised when their tanks show signs of overfeeding; actually, this is one of the most common ways people overfeed. Fish are naturally grazers or ‘nibblers’ of food, and are not really equipped to eat single large meals. When they are fed in this way, they will eat their fill and leave over the rest. This will not only lead to large amounts of food waste in the tank, but will also mean that fish are left malnourished in between feedings. Ideally then, schedules which include multiple small feedings will keep your fish healthy. Always make sure that everyone in your household is aware of the feeding schedule so that the fish aren’t accidentally fed again by different family members.

Next, making sure you feed the correct quantity during these meal times is critical. This will greatly depend on the specific needs of your fish. The best way to determine appropriate meal sizes is to carefully observe the eating habits of your fish. Begin by feeding very small quantities (as small as three or four flakes per fish). If this amount is consumed in a matter of minutes you may add more and observe again. In general, any food that is not eaten within five minutes will not be eaten at all. One of the most common feeding mistakes people make is feeding the tank rather than the fish; that is to say that people tend to feed more if the tank is large, regardless of the actual amount of fish inhabiting it. Make sure you consider this when sprinkling in your pets’ meals.

The quality of the food you choose is also important. A food which is low quality, stale, or simply inappropriate for your specific fish, will likely go uneaten and can cause some of the same problems discussed above. Different species of fish have different requirements and preferences (for example, whether their food is in flakes or pellets, whether it floats or sinks). It is therefore essential to learn all you can about the dietary needs of the various types of fish that inhabit your aquarium.

Finally, and because mistakes do happen, it is always a good idea to practice methods of removing excess food waste. This includes having a good quality filter, but can also involve regular siphoning or use of a net to skim the bottom of the tank. Including a ‘scavenger’ species in your aquarium (such as a catfish) can also help to clear any food that has fallen into otherwise inaccessible areas of the tank.
Perhaps the most unfortunate part about losing fish to overfeeding is the fact that it be can be prevented. As easy as it may be to over-feed our fish, it is also easy to avoid it. By being observant, educated, and just a little bit cautious, you can ensure that your fish are always happy and healthy, without being hungry.

By Alison Norwich – Pets.ca writer