There are a lot of things to keep in mind when shopping for fish with a brand new tank. Did you set up your tank correctly? If you’re getting tropical fish, did you buy a heater? Do you know the temperature range to keep your water around? What type of fish get along the best? Which fish get along?
It can seem very overwhelming, but if you take things one step at a time, you’ll have no problem getting your tank started.
Firstly, decide which kind of environment you’d like. If you’d like slower and more gentle fish, you’d probably like to have either cold, fresh water with bigger goldfish and goldfish variants, or a warm, fresh water tank with “community” tropical fish. I personally have a 30 gallon tank with 10 community tropical fish. Community fish do not fight each other and generally drift around at a slow pace. Goldfish typically do not fight each other.
Never, never ever put a Beta fish in the same tank as other regular goldfish. Yes, Betas are good looking fish, but they will viciously kill any other fish they come across, and if they cannot kill it, they’ll die trying. If you are unsure what a Beta fish is, they generally are sold alone, with no other fish. If you still cannot tell, ask an employee at the local pet shop. Also, never try to put more than one Beta fish in the same tank, if you plan to keep a Beta fish. They’ll fight to the death.
Another option is to buy aggressive fish, but you absolutely, positively need to know which will get along with which. Only buy aggressive fish types that will get along with fish you already have or plan on getting. Please don’t ever test their boundaries, it’s a very bad idea.
Make sure your tank is appropriate for the number of fish you are getting as well as the type of fish you are getting. There’s typically no such thing as too much room. Make sure to buy more than one of a certain kind of fish if it survives best with partners. I’ve got a few pairs of certain types in my tank, and they’re literally always by each other. If you have fish that are smaller types, be sure to buy lots of things for them to hide around. I had a very small fish who used to hide in his little castle, and only come out to eat. Now he is pretty big and swims around on his own, not afraid to be with the other, bigger fish.
It can be really tempting to buy some of those neat looking aquatic animals at the pet store. There are a few rules to follow when getting these, however. For example, never put a post-molting crayfish in a tank with other fish. Once the crayfish has gained its new body, it becomes vicious. I know this from firsthand experience and unfortunately lost a very beautiful neon fish to it. Don’t learn the hard way like I did! Make sure you ask around before buying these special sea creatures.
As one last word of advice, make sure your brand new tank runs itself with filters and any “toys” or rocks for a day or two before adding fish, it helps establish it.
When you take the proper precautions, starting a new tank can be very simple.