For freshwater tanks, 10% of the water should be removed and replaced every week and once a month, 25% of the water should be removed and replaced. Make sure that the water is the same temperature so as not to shock your fish.Saltwater tanks are a bit different. Remove 20% of the water once a month or 5% every week and replace with prepared salt water.
Feed your fish regularly
Until your tank is well established you should feed your fish once a day. As time goes on, you can give them smaller amounts throughout the day.
There are special considerations for saltwater fish that are wild caught. Because they’re not used to eating aquarium food, they should be slowly acclimated to it over a few weeks.
Food is the main source of waste in your tank so be very careful not to overfeed. Not only does the water get dirty faster but too much food is harmful to your fish.
The standard rule is to give your fish only what they can consume in three to five minutes. If there’s any food left, you’re overfeeding.
Keep a close eye on the temperature
Tropical fish require a temperature between 74 and 82 degrees fahrenheit. Most fish tank heater automatically maintain the ideal temperature but it’s a good idea to get in the habit of checking.
Test the water every week.
There are a lot of different testing kits you can use right at home or you can take a sample to your local pet store and have them test it for you. Specifically, you should be looking for pH, ammonia, nitrates, nitrites, and chlorine levels for freshwater. Saltwater tanks have more specific requirements and require special testing kits. Some saltwater fish also have special requirements you might have to check for. If any levels are elevated, the easiest way to correct it is to remove and replace some of the water until everything is closer to where it should be.
Clean the tank weekly
Every week you should clean the inside walls to clear away any algae. Make sure you use the right scrubber, especially if you have an acrylic tank that can be easily scratched.
Check the filter every month
Rinse the filter floss in discarded tank water and replace the carbon and other disposable media. Make sure the pump is working appropriately, too, and that the intake isn’t blocked with anything.
Take care of plant life.
Dead leaves and plants can throw off the water balance by adding more debris and ammonia. Make sure you tend to them regularly and remove any brown or dying leaves.