So basically there are two kind of aquatic pets available for aquarium in the market. They are Salt water aquatic animals and fresh water aquatics animal. They cant coexist, salt water and fresh water fishes haves different requirements. Do some independent research on particular type of fishes you want to keep before buying anyone of them, you should buy all the equipment required by the fish species you want and set up the fish tank before you buy any fishes. Because once you brought new fishes, you need to put them into tank as soon as possible.

So how to buy a fish pet? How to choose them? by doing some research you probably should know how to select the fishes. When visiting fish aquarium pet store, browse through variety of fishes available and ask the pet store owner, or sales person about which fish can coexist with which fish. This is important, if it is not researched properly, fishes brought to the fish tank can try to kill each other. So you’ll lose some fishes and lose money. Thus, ask the fish keeper to let you know which fish can live in the same aquarium, or by doing some research yourself, because there are too many variety of fishes, I can’t possibly tell all here. Some example of it is like goldfish or carp which is herbivores cant be put into same fish tank with carnivores fishes like piranha. Besides, angel fish can’t mixed with small fishes, angel fish will eat them. you get the point.

Buying fish can be tricky sometimes, the best way to do it is to observe each fish you buy, make sure the fish active and healthy. Healthy fish haves clean smooth fish scale, and bright eyes. Healthy fishes always swim around (well, it depends on certain species). Try to observe when the fish keeper put a net into the aquarium fish tank, healthy fish should be alert. And move away from the net, for those which does not react properly probably have some health problem. Besides, if you notice there is death fish or sick fishes inside the aquarium, never buy any fishes in those tanks (even the ones that looks healthy), the whole fish tank probably is infected with certain disease or parasite. Avoid this as possible as you can because once you buy the fish and put it in your aquarium, you are risking your current other aquatic animals as well.  

Ask for a good bargain, sometimes in certain pet store it allows price deduction, if you are seeking for cheap fishes ask for stock clearance one, because some fishkeeper if looking for ways to get rid of certain fish especially those with only 2 to 3 fish in one tank, it is a waste of spaces, while the other hand they cant mix with other fish. those fish keeper will try to get rid of them and fills in new species of fish into the current aquarium. This happens occasionally, if those clearance fish suites you, you can get it pretty cheap. Besides that, you can also buy lots of aquarium products such as fish food, pellets and fishes, or even fish tank. Then ask for discount, they usually give some discount for buying many items at once.

In some occasion you might have the feel to get rid of certain fishes. Those were he times you get bored with the fish species. Consider fish trade in… although this is rarer case, some fish store offer fish trade in but those are usually only for unique species, Not all of the shop allows, so ask for it whether they accept trade in.