If you’re looking to add fish to an existing aquarium or want tankmates for your new fish, research what fish do well together first. Some fish have a reputation for being aggressive towards others and some might just be shy around different species. It can also be a good idea to know how to tell the sex of your fish of choice. Some fish, like guppies or platys, are prolific breeders and if you keep males with females you might end up with a huge amount of unwanted fish babies. Know how to identify them so you can buy fish of only one sex if needed.
It’s critical to set up a tank beforehand due to the nitrogen cycle in the water. Cycling a tank means having the right bacteria in the water to establish a nitrogen cycle. This helps keep the water safe and stable for your fish, otherwise the ammonia levels in the water can become toxic in mere days after adding fish.
Fish may be sick if they have one or more of these symptoms: Clamped fins Heavy breathing or gasping at the surface Inactivity Flashing, or scratching itself on rocks, ornaments, or sand. A bloated belly or scales are pointed outward like a pine cone Inability to swim properly Loss of color Stringy or cottony patches on their scales Small white spots on their body Check the fish for signs of injury, like torn or missing fins. These wounds often heal on their own, but leave the fish vulnerable to infections that can be much more difficult to treat. If you want to take these fish home, you have to know how to take care of them. Research how to treat different fish diseases and what medications you might need.
If one tank in particular has a lot of dead fish, there is likely a disease outbreak or other issues with the tank. Avoid purchasing any fish from these tanks.
Consider asking the employee what the water conditions in the tank are like. If the pH, temperature, or salinity are drastically different from your tank at home, you might have a harder time acclimating your new fish. [4] X Research source
If you’re looking for a specific species of fish, consider buying directly from breeders.
If any of your fish arrive dead or noticeably ill, take some pictures as proof and contact the seller as soon as you can. Most refunds require evidence of the fish in question and need to be processed quickly.
