Acclimate your fish to the water. Keep pH and other chemical levels in balance. Make sure the water temperature is correct. Clean tank glass and other structures.
Choose the right size for your tank. Regularly monitoring the water conditions in your aquarium or tank is a good start to proper maintenance, but there are other things you can do, including regular cleanings. Plan to replace 25 percent of the water in your aquarium once a month. This will help keep tank water clean and nitrate concentrations at a safe level.
A gravel vacuum can help remove water and debris, especially those found at the bottom of the tank. Also watch out for algae buildup. This could appear as a cloud on the glass of the tank, or the water itself could look cloudy, causing a decrease in oxygen levels in the water. To help clean algae from your aquarium, use a brush to scrub tanks or an aquarium algae magnet.
Once a week, clean the inside of the front glass (and the side glass if desired), change 10 to 15 percent of the water, and clean the outside of the glass. You can do this every ten days, but it's usually easier to remember it if you perform maintenance on the same day of the week. Visit your local Petco store for advice on what size aquarium or tank will be right for you based on your space availability and the type of fish you expected to find. The amount of basic aquarium maintenance you must perform is directly related to the degree of compliance with the three rules of aquaculture.
Fortunately, fish are fairly easy to care for as long as you choose fish that go well together and put them in a large enough tank. Since fish tank sizes range from desktop aquariums for a single beta to a large aquarium suitable for various types of fish, it's important to think a bit about the habitat before bringing home any type of aquatic life. The size of the aquarium you need will depend on the type of fish you decide to bring home (consider whether it will be a freshwater fish, a saltwater fish and the individual species) and how many you want to get.