Most aquarium fish need to be fed once or twice daily, with the frequency depending on species, age, and tank conditions. Adult fish typically thrive on one feeding per day, while younger or more active fish may benefit from two smaller meals. The key is feeding only what they can consume in a few minutes—overfeeding is the most common mistake in fishkeeping and leads to poor water quality and health problems. Some species, like goldfish and plecos, are constant foragers and do well with once-daily feeding, while others, such as young cichlids or bettas, may perform better with two meals. Fasting one day per week is actually beneficial for most fish, as it allows their digestive systems to rest and helps maintain water quality. Tank size, filtration capacity, and water temperature also influence feeding needs—warmer water increases metabolism, requiring more frequent feeding, while cooler water decreases it. Live plants in the tank can supplement nutrition for some herbivorous species. The best approach is to observe your specific fish's behavior: they should eagerly eat all food within minutes, and their belly should appear gently rounded, not bloated.