Food

The key to keeping your fish healthy and happy is providing them with proper nutrition. While many fish can thrive on basic flake food, variety is essential to ensure they get all the nutrients they need. Some fish, especially in saltwater tanks where many species are wild-caught, can be picky eaters and might not even recognize flakes or pellets as food. The most important factor is that the food is accepted and eaten by the fish. If they don't recognize it as food, it won't nourish them.

The fishkeeping hobby has a long history, which means there are a wide variety of food options available. Each food type has its pros and cons, and it's essential to understand which will best meet your fish's needs. The three main categories of fish food are prepared foods, frozen foods, and live foods.

Feeding Guidelines: The Importance of Moderation

Overfeeding is one of the most common issues in aquarium care. Excess food leads to excess nutrients in the water, which can cause ammonia and nitrate spikes. Decomposing food contributes to this problem, making overfeeding a major factor in poor water quality.

As a general rule, only feed your fish what they can eat within a few minutes, and avoid leaving uneaten food in the tank. If you have bottom feeders, a slightly larger feeding may be necessary to ensure they have food to scavenge. However, be cautious not to overfeed.

When cycling your tank with fish (fish-in cycling), feeding every other day or every third day is sufficient, as fish are cold-blooded and can go without food for longer periods.

If you're going to be away for an extended period, don’t worry—most fish can go without food for up to a week. Just ensure they’re fed properly before you leave, and they should be fine until your return.

Prepared Foods

Prepared foods are a staple in many aquariums, with fish flakes being the most common. While they are convenient and can be a suitable diet for many fish, there are some potential drawbacks to consider, especially if they're fed too frequently without variety. One of the main issues is that freshwater fish don’t drink water—they absorb it through their gills. Dry foods like pellets and flakes can lead to constipation or impaction. To visualize this, think of eating dry bread without drinking anything. It would be hard to digest, right? Similarly, offering frozen or live foods regularly can help prevent these digestive issues and provide additional nutrition for your fish.

For saltwater fish, which do drink water, prepared foods can still be a good option, but supplementing with frozen or live foods is beneficial for engaging the fish and offering a more complete, balanced diet.

Another common issue with prepared foods is the presence of fillers, such as ash. While fillers aren’t harmful, they don't provide nutritional value and pass through the fish undigested, ultimately contributing to waste buildup in the tank. Lower-quality foods tend to have higher filler content and can lead to dirty water, so it’s important to invest in higher-quality food options. These foods are generally richer in protein and lower in filler content.

Many prepared foods are marketed for specific types of fish, such as cichlids, but most fish with similar dietary needs (carnivores, omnivores, herbivores) can thrive on a variety of foods. For example, I recommend cichlid pellets for goldfish, as they are easier for goldfish to digest, reducing the risk of constipation. Omnivores, which make up the majority of fish species, require both protein and plant material. While they will naturally graze on algae, supplementation may be necessary if algae is scarce. Tangs, in particular, are prone to nutrient deficiencies without enough plant matter, leading to conditions like HLLE (Head and Lateral Line Erosion).

To ensure omnivores get enough vegetables, you can supplement with fresh, blanched vegetables like peas, carrots, and cucumbers. For saltwater tanks, nori (seaweed) is an excellent option for omnivores like tangs. Offering these vegetables ensures a balanced diet for fish and helps prevent health issues.

Frozen Foods

Frozen foods are an excellent supplement to a prepared food diet, and they are especially beneficial for pickier eaters. Many fish prefer the texture and taste of frozen foods, as they more closely mimic their natural food sources. Frozen foods, which are typically high in moisture and contain whole animal parts, can help prevent constipation in fish, especially in freshwater aquariums.

Offering frozen foods like brine shrimp, bloodworms, and daphnia is a great way to provide variety and nutrition for your fish. Even fish that typically accept prepared foods will often get excited about the addition of frozen options.

Live Foods

Live foods are sometimes essential for species that won’t accept prepared or frozen foods. For example, seahorses require a constant supply of live foods like copepods and baby brine shrimp to stay healthy. Live foods can be challenging to culture, but there are several options that can be easily maintained in your aquarium.

Common live foods include daphnia, pest snails, vinegar eels, and brine shrimp. While brine shrimp can be bought as eggs and hatch in your aquarium, some hobbyists prefer to culture them for a steady supply. Live foods are particularly important for species like pufferfish, which need them to wear down their teeth and prevent overgrowth.