Often times the first questions aquarists ask, especially those who are new to the hobby, are about feeding. What do I feed my fish, how much should I feed them, and how often? In nature, what fish eat depends on whether they're herbivores (plant eaters), carnivores (meat eaters) or omnivores (both). How often and how much they eat depends on their dietary preferences, their appetite and availability of food. Here are some tips to help provide the best possible feeding program for your fish:
Herbivorous fish tend to forage throughout the day because it takes a lot more plant material to satisfy their nutritional needs than the amount of meat protein for carnivores.
Omnivorous fish have it best because they have many more options for suitable food items. Predators and specialized feeders eat more when food is abundant, but when it isn't several days may pass between meals. This could explain why aquarium fish readily accept food anytime it's offered; they don't know when their next meal will be!
Carnivorous fish eat less frequently. This is because they are less likely to catch food every day in nature, and their aquarium feeding schedule should match that.
What Should I Feed My Fish?
It's important to know what your fish eat in nature and feed accordingly. Are they herbivores, carnivores or omnivores? Most aquarists keep a variety of species in their aquariums, so offering a combination of different foods is best. For example, livebearers are largely herbivores, while tetras are more carnivorous. If you keep both types of fish in your aquarium, as many aquarists do, alternate feedings of meat protein and plant-based foods to keep everyone happy and healthy. Variety is important regardless of what types of fish you keep, as even carnivores benefit from some plant matter in their diet, and vice versa.
The size of the food you feed should match the size of your fishes' mouths. In other words, large predatory fish will usually show no interest in small flake crumbles, and small fish like Neon Tetras can't fit large pellets into their mouths. Uneaten food will quickly pollute your aquarium.
When feeding frozen foods, dispense food a little at a time using a turkey baster or large syringe to make sure everyone gets some. Drop a little food at the surface for top feeders and gently squirt some lower into the water column for mid-water and bottom feeders.
How Much Should I Feed My Fish?
It's always best to underfeed, especially in new aquariums, as uneaten food can cloud your water and cause dangerous rises in ammonia and nitrite levels. A general rule of thumb is to feed only what your fish can consume in 2 to 3 minutes. When in doubt, start with a tiny quantity and observe how fast your fish consume it. If it is completely consumed in less than 2 minutes, give them a little more. It won't take long to figure out how much food to give them at each feeding. Remove any food that remains after five minutes with a siphon hose or net.
Another consideration is what part of the water column your fish feed in. Fish can be:
- Surface feeders
- Bottom feeders
Most fish will learn to take food wherever it's available, but shy fish may wait until food drifts into their "safe zone". These fish may need to be target fed, meaning directing food right to them. Flakes and some pellet foods typically linger at the surface for a minute or two before beginning a slow descent to the bottom, making them good choices for surface and mid-water feeders. Soaking dried foods or "swishing" them at the surface will help them drop faster for mid-water feeders. Most , and other bottom feeders do best on sinking tablets, wafers and pellet foods.
How Often Should I Feed My Fish?
For the most part, feeding your fish once or twice a day is sufficient. Some hobbyists even fast their fish one or two days a week to allow them to clear their digestive systems. Larger, more sedentary fish can go longer between meals than smaller, more active fish. Herbivores forage throughout the day, so they should be fed more frequently, however, only small quantities at a time. Small active fish like danios and newly hatched fry have higher metabolic rates and should be fed frequently, especially when kept at warmer temperatures. Water temperature regulates fishes' metabolisms and influences how often and how much they need to be fed.
When Should I Feed My Fish?
In nature, most fish feed in the early morning and at dusk. Exceptions are herbivores and omnivores that forage throughout the day, and nocturnal species. Although aquarium fish can be fed at any time of day, morning and evening feedings are best. They quickly learn when "feeding time" is, eagerly swimming back and forth at the surface or emerging from hiding places in anticipation of their next meal.
Make sure the aquarium light has been on for at least 30 minutes before the morning feeding and leave it on for at least 30 minutes after the evening feeding. Nocturnal species such as knifefish, catfish and certain plecostomus can be fed sinking foods shortly after the aquarium light is turned off at night.
What Are the Signs of Overfeeding Fish?
The term "overfeeding" means feeding more food than your fish needs or wants to eat in one feeding. Even hobbyists who only feed once a day or every other day can be guilty of overfeeding if the food is not completely consumed in less than 2 or 3 minutes. Here are some tell-tale signs of overfeeding:
- Uneaten food remains in the aquarium after 5 minutes, but the fish show no interest in it. In extreme cases, a fuzzy or cottony white fungus may begin to grow on the bottom or on decorations and plants.
- Aquarium water is cloudy or hazy and has a foul odor to it. Foam or froth may be present on the surface.
- Filter media becomes clogged in a matter of days after cleaning.
- Excessive algae growth. Even with proper filtration and water changes, nitrate and phosphate accumulation from heavy feeding can contribute to
- Ammonia or nitrite levels are elevated.
- Chronically high nitrates or low pH.
If your aquarium shows signs of overfeeding, siphon out any uneaten food, lightly vacuum the substrate and reduce the amount of food per feeding by 50%.
Providing your fish with the right diet and feeding schedule will ensure growth, disease resistance, vibrant colors, and long, healthy lives.