Overfeeding the fish – its consequences and preventive measures

Overfeeding the fish - its consequences and preventive measures

One of the most common mistakes that almost every new aquarist make is- Overfeeding! Although this gaffe is quite common, it could lead to many harmful consequences, among which the death of fish is one. Accumulation of the uneaten food and increased waste products in the tank is very harmful to the health and well-being of the swirling creatures.

As per a report, overfeeding is the major reason behind the loss of fish in an aquarium.

The problem of overfeeding the fish is more common in beginners. The three major reasons behind are:

  • Thinking their diet is as huge as humans and supplying more food in the tank.
  • Feeding is one of the best modes of communication with them; doing it too often seems exciting.
  • Fish express enthrallment and eagerness when humans approach them and swim to the top or front of the tank. It sometimes looks like they are hungry which made the beginners feed more.

All these temps the aquarists to supply more than the required to the fish. However, on the contrary, the stomach of these small creatures is so tiny that they need a very little amount of feed.

What are the problems associated with overfeeding

When you give extra food to the fish, they overfeed which leads to the production of excess waste product. Some of the uneaten food also accumulates in the tank that changes the water chemistry. Waste products and uneaten food breakdown into chemicals that increase the toxicity of the water.  It eventually stresses the fish, creating health issues and different types of diseases in them.

Other than the fish’s health, the tank also becomes unsightly and unpleasant to the eyes. The aesthetic view of the aquarium gets deteriorated drastically.

Some major problems or the consequences that fish face with an overdose of fish feed-

  • Increase in the level of ammonia and nitrates due to the breakdown of uneaten food and waste products making the water toxic for fish.
  • Decrease in the level of oxygen as decaying of the excess of waste products will require more oxygen for decomposition. Therefore, less dissolved oxygen will be available for the use of fish.
  • Decrease in the pH level due to more acid production.
  • Development of fin rot or tail rot in fish which occurs majorly when they remain in stress for longer durations.
  • Fatty liver due to overeating which affects the normal functioning of the fish. It is common in African Cichlids and rainbow fish.
  • Problem in digesting as the bacteria become no longer available to do the needful.

These are some common problems with which fish had to deal when you overfeed them. Other than these, the tank also suffers greatly, and its aesthetic value diminishes completely. Some major problems that arise are:

  • Algae Bloom- It occurs mainly when there is an excess of food in the tank and waste products take too much time to decompose.
  • Cloudy water- The large quantity of decaying organic material worsens the quality of water making it unclear and hazy.
  • Mold development- Sometimes gravel and decorative items inside the tank develop white cottony thing which is mold or fungus.
  • Flat Worms or Planaria- The emergence or development of Planaria is quite common when the quality of water deteriorates. Overfeeding tanks have higher chances of their development. Although not harmful, they feed on fish eggs.
  • Clogged filters- The function of filters is to purify the water, remove the normal amount of waste and enhance the water quality. However, when the excess of waste products accumulate, they overpower the filters and clog them. This reduces their capacity to function normally.

How to avoid overfeeding

Consequences of overfeeding are the biggest motivation to stop overfeeding once and for all. Every aquarist wants his fish to remain healthy, happy and stress-free. Therefore, the first step is to understand how much fish food your swirling creatures require. Inculcating good feeding schedule and dose will help in avoiding overfeeding and its consequences.

Try the following steps to prevent overfeeding:

  • Maintain a feeding schedule- A proper feeding schedule with an appropriate interval of time makes a lot of things easy. It will train your fish and tell them the specific time of the day to get the food. Generally feeding twice in a day is advisable but you can also go for smaller feeds at frequent intervals. Fish prefer nibbling small chunks than gulping large amount at once.
  • Give them the right amount of food- The idea of the right amount comes from experience. You need to watch the fish between the feeding intervals and the amount of food left uneaten in the tank. It is advised to start with a small amount and gradually increase the dose when you see all the food finished.

The thumb rule says to feed only the amount that they eat within 4-5 minutes of feeding.  After 5 minutes the food which is left, generally remain uneaten. At the same time, keep an eye on the fish as well as for whether all of them are eating or not. While some munch on the food quickly, some like scavengers take time. If some of the fish are not eating at all, it could be the sign of them being ill.

  • Give them the right food- Apart from scheduling the feeding and giving the proper amount, feeding the right food is also very important for the fish. Low quality or stale food will not only make them undernourished and unhealthy but will also lead to more waste as fish will not eat them.
  • Give them in the right size and proportion- The food should be given in the right size and form. Generally fish prefer food in the form of flakes. Size of the flakes should be in consideration as well. Some fish like to munch on floating food, and some prefer the food that sinks. So, you need to research thoroughly before feeding your fish for their good health and digestion. Make sure you always feed fresh and high-quality food.


  • Sometimes aquarists feed based on the size of their tank, which is a wrong practice. The feed should be given as per the number of the inhabitants of the tank and not as per its size.
  • If you are switching to a new food, feed sparingly as the fish take time to identify their new diet and accustom to them.

How to protect your tank from uneaten food

If the fish have not eaten a large amount of food, it is advised to remove those chunks immediately. You can use a fine net or a siphon for the purpose. No matter what is the size of your filtration system, you still can do your part to make the tank clear.

If you think you have overfed your fish, siphon out around 25% of the water from the aquarium. Remove the debris from the substrate. It will decrease the amount of feed in the water.

Make sure you use the perfect filtration system for your tank. It is a one-time investment. So make sure you get the best and as per the size of your tank so that it can resolve most of the problem of overfeeding- an excess of waste materials and uneaten food.

You can also include some scavenging inhabitants in your tank. Catfish and loaches are the best picks for this purpose. Invertebrates can also deal with the excess of waste materials and uneaten food left in the tank. Although the scavenging inhabitants will not fix the problem entirely, they will assist in improving the water quality and condition of the tank to a great extent. Moreover, they will also remove the uneaten food from the areas of the tank where siphon or fine net cannot go.

Try that only one member of the family is engaged in feeding the fish. When the same person is in charge of feeding every day, it will rule out the dilemma of whether the fish are getting the proper diet or not. You can mark on the calendar to avoid the chances of duplicate feeding.

Final words:

Overfeeding could be detrimental. It not only affects the health of the fish but also decreases the aesthetic value of the aquarium. Therefore, feeding the right amount, at the right time and the right food is very important.

While with fish keeping most of the things come with experience, proper research and a good insight into the matter can save the life of fish and make your hobby fun and frolic. So, keep the above points in handy and maintain a great aquarium ambiance.

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