The amount of food to feed your fish will depend on the species, size, and age of the fish, as well as the type of food you are feeding. Overfeeding can lead to water quality issues, while underfeeding can lead to malnourishment and health problems in your fish.
As a general guideline, most fish should be fed 1-2 times per day, with an amount of food that they can consume in 2-3 minutes. It's better to feed small amounts of food multiple times a day than to feed one large meal. This will help to prevent overfeeding and reduce the amount of uneaten food that falls to the bottom of the tank.
It's also important to vary the diet of your fish and provide a balanced diet that includes both dry and frozen foods. This will help to ensure that your fish are getting all of the necessary nutrients they need to stay healthy.
As you get to know your fish and their eating habits, you can adjust the amount and frequency of their feedings accordingly. Remember to always monitor the water quality in your tank and make adjustments as needed to maintain a healthy and balanced ecosystem for your fish.