When you test your ammonia in the tank, an ideal level is below 0. 25ppm.

If you go with a fish species that prefer to live in schools or shoals, like tetras, plan to purchase at least five of them at once. Schooling fish swim together, whereas shoaling fish only swim together when afraid. Both fish need companions to feel safe.

For example, goldfish, guppies, and tiger pleco are all friendly fish that will coexist peacefully together. Angelfish and cichlids are two types of aggressive fish that can often live in a tank together without harming one another.

If you do go the online route, choose a dealer that offers clear customer service connections via email or the phone. Look for positive reviews online as well. These can often be found in fish owner forums. Avoid wild-caught whenever possible. Wild-caught fish are often more sensitive, caught in inhumane ways, and harder to care for. As soon as you receive a fish from online, or before buying it in the store, look to make sure that it appears healthy. It should be active and swimming around at a steady pace. The eyes and gills should be clear of debris or mucus. The scales should be intact and scratch-free. [6] X Research source

When in doubt it’s better to get a slightly larger tank, as overcrowding can cause a number of health problems for fish. It can even lead to fish deaths due to poor water quality. Make sure to base your calculations on your fish’s full adult size, not their current size.

It’s also a good idea to not smoke in the same room as your fish, as this damages the air quality. If you have other pets or if your fish jump, remember to get a lid for your tank.

It’s important to place your tank near a functioning electrical socket, as you’ll need to plug in devices like your heater, light, and filter.

A mechanical filter is generally the best option for a beginner, as they are fairly basic. Some filters should be placed under the gravel in your tank, whereas others hang from the back of your tank. [11] X Research source There are also canister filters, which go inside the tank. Only clean the first filter media, near the back of the filter. It only needs cleaning if it’s full of debris. Otherwise DO NOT clean the filter! This will cause ammonia and nitrite spikes and could kill your fish. The filter media will grow beneficial brown bacteria on it, which removes toxic chemicals from the fish waste. It is essential to keeping your fish alive.

Try to balance out your decorations by placing taller or larger pieces towards the back of the tank. This will also make it easier to view your fish in action. Make sure that your decorations don’t have sharp edges, plastic pieces that can break off, or paint that might flake. [14] X Research source

Once the water is in your tank, put some fish food in and wait until brown beneficial bacteria is growing on the filter media. Test your water qualities. Once the ammonia and nitrites are 0ppm and the nitrates are below 20ppm, you can acclimate the fish. The tank usually will take six weeks to cycle, but the process can be sped up by adding beneficial bacteria or used filter media.

Some fish, such as otocinclus, require drip-acclimation. To do this, tie a knot in air tubing and start a siphon by putting one end in the tank and sucking on the other end. Place the end you were sucking on into the bag with the fish. The water should slowly drip into the bag. Drip acclimate for about 30 minutes. Don’t skip this step as it helps to acclimate your fish to the new water qualities and temperature. It reduces the risk of shock. [22] X Expert Source Craig MortonAquarium Specialist, Aquarium Doctor Inc. Expert Interview. 21 July 2020.

Excess food can cause all sorts of problems, including clogging filters, ammonia and nitrite spikes, and contributing to algae growth. Feeding the right type of food is important as well. Most fish to well with flakes or freeze-dried food, but some bottom feeders will require sinking pellets.

Remember to only clean the first filter media; the one closest to the back. If you clean all of it, your ammonia and nitrite levels will rise because you removed all the beneficial bacteria.

Make sure to remove any dead fish from the tank immediately. Most medications should never be added as a preventative measure.