Buying Fish
When buying any fish from a pet store, there are a couple things that you should look for. Look at all the fish in the tank, do any of them have white spots on them? This could be a parasitic infection know as ick, there are many medications that will treat this parasite, but if the fish has to much on it, it could be potentially fatal. Even if the fish you want doesn't have it on it at the time, if the other fish in the tank do, that fish to will most likely get it too. If it is a "special" fish, and you have to have that one. Then I would suggest a quarantine tank, so not to give the parasite to any healthy fish in your main tank. Be ready to do battle with the parasite if your new fish does become infected. A good length of time to leave the fish in the quarantine tank is 2-3 weeks, if at the end of that time you see no abnormalities then it is possible to add the new fish to the main tank.
Something else that you might see in tanks at pet stores is dead fish, be leery of these tanks. It could be that the store just got a new shipment and the fish didn't make it through the shipment, but it could also be that there is either a parasitic or bacterial infection in the tank. If you are leery, ask a person at the store when the last shipment came in.
Good luck in getting you new fish and I hope you have great success with each and every one that you get!
