Another aquatic supply you'll need for your fish tank is a fish net. I'd actually advise getting a couple of fish nets for your aquarium. Personally, I have two nets.
If you only buy one fish net, you may find yourself in a couple of situations. Let's say you need to corral a fish that is too big, but the fish net you have is too small. Or, you may face having a hole that's too small to put a large fish net through.
By getting a minimum of two, and possibly three fish nets in your arsenal of fish supplies, you avoid these situations. Nets are relatively inexpensive. You sure don't want to bring your live fish home from the fish store and find you can't get him in his new dwelling, because the net won't fit.
The size of your fish tank and how many tanks you have, will determine the sizes of fish nets you purchase. If the 2" fish you buy is capable of growing to 8" or longer, you better add a big fish net to your supply of fish-keeping equipment too!
An essential supply for a fish tank keeper is a bucket. The bucket should only be used for your fish. That means don't go mopping your floors and using your fish bucket to keep the water in.
It's nice to have a fish bucket in your arsenal of fish tank supplies. It can be used to hold your other tank supplies, transport fish, acclimate them, and use it to add water to your aquarium.
I recently used this handy supply to acclimate my new Crowntail Betta. He needed to get used to the water before putting him in his fish tank and installing it.
A fish supply bucket should be in every serious fish keepers supply list.
Never ever use your fish supply bucket for anything else than your fish tank maintenance. Ever. Ok, I've probably made that clear. Obviously you will be setting up, or have set up an environment for your fish that is stable. You don't want to kill them by introducing something foreign they might not like. Like detergent!
I've marked the outside of my bucket, FISH ONLY. I'd advise doing the same, and storing it with your other fish tank supplies.