First off, it helps to know a little bit about the fish you are buying before taking it home. This way you will know what the fish should look like and what kind of behavior to expect. You should examine the fish closely before it even leaves the store. Here are some things to look for when you're at the fish store:
- Examine the fish closely for any type of white spots or fungus
- Look at the eyes of the fish. Make sure they are not cloudy or show signs of pop-eye (a condition where the eye of the fish looks like it it popping out)
- Examine the fish closely for any torn or missing fins-Are the fish swimming normally? or are they exhibiting some sort of unusual behavior.-How are the other fish in the tank? Do any of them have signs of illness or disease? If so, don't purchase any fish in that tank since you don't know what may have spread.
- Are there any dead fish in the tank? If so, it's a good idea to stay away from any fish in that tank.
- Another thing you may want to ask is what type of filtration system the store contains. Many large stores may have a central filtration system where several tanks are sharing the same water. If this is the case, then if one tank shows signs of ick or disease, there is a good chance the water quality in the other tanks sharing that water could be impacted.
- Make sure to do your homework before bringing any fish species home. If you don't know how big the fish will get, or if he'll attack and kill the other fish in your home aquarium, do some research before taking that fish home.