If you have an aquarium, then you want to make sure all of the fish in it are healthy. The temptation is to use “fish flakes” exclusively – but this is not always the best diet for all fish at all times. Here are some things to consider:
Fish need fiber. Insufficient fiber can lead to swim bladder syndrome – you suddenly find your precious fish swimming upside down near the surface of the tank because they can no longer control the amount of air in their swim bladder because of constipation. (Pro tip: Feeding peas can help relieve swim bladder syndrome symptoms quickly).
You would not feed a dog exactly the same food every day – so why feed your fish the same thing. Although prepared fish food is nutritious, your fish will benefit from being fed different dry or canned food and also from frozen or freeze-dried food three or four times a week to make sure that they get all of the different nutrients they need.
The biggest problem is that people overfeed their fish. Most aquarium fish can actually go as long as a week without eating. A good rule of thumb is to select one day a week on which you simply do not feed the fish. If there is uneaten food in the tank, remove it quickly as it can rapidly cause the pH of the water to drop and a nitrate and ammonia build-up that can be life-threatening to your fish or cause the growth of mold and/or algae in your tank. It’s best to err on the side of underfeeding your fish and then give them another sprinkle if they have eaten it all within half a minute or so. (Healthy fish will gobble up food quickly).
If you have more herbivorous fish in your tank they will want to graze, just the same as land-based herbivores. Plant some edible plants for them to nibble on. (However, some species will voraciously devour any plants in the tank down to the roots quickly). Fish that like to nibble will be mentally healthier if provided with the means to do so and properly-chosen plants will also make your aquarium more attractive.
5. Live feed.
Be very careful with live feed, especially with feeder fish, as it can be a vector for disease. Choose live feed carefully and never feed only the same kind of food.
6. Other food.
Raw meat and fresh vegetables make great treats for your fish, but do your research to ensure that they are species appropriate. As it can be hard to provide fish with a balanced diet if you try to “design” it yourself, consider feeding these as a supplement to commercial fish food.
7. Moisten freeze-dried food.
As a note, if you feed freeze-dried food, it should be moistened before being offered to your fish. It will continue to absorb water after you put it in the tank and this can sometimes result in fish eating more than they intended to and becoming sick.
8. Use species-appropriate pellets.
When feeding pellets, consider the fish you have in your tank. Some fish like to feed off the surface whilst others prefer it if their food sinks to the bottom. Using different pellet weights can also let you provide a different diet to different fish. Sinking tablets are particularly useful if you have catfish or other bottom feeders.
The bottom line is to remember that healthy fish are always hungry and not overfeed them and to provide fish, the same as any other pet, with a varied and balanced diet. And never leave uneaten food in the tank.