Have you talked to the store about how you intend to use the $50. Use the certificate, but have them hold a credit for the purchase of the fish. That way they've got their money, but it allows you to come back and get the fish when the tank is ready. If it's a pet store that cares about their fish, they'll allow you do do this.

Be sure to observe the fish once they're together. Barbs are aggressive and may try to eat the shrimp...........and harrass the goldfish.

Any way you can add to the certificate and get a 5 gal tank instead? Everyone will be much happier and healthier.

I agree with Ann about the size of the tank. A 2 gallon aquarium won't really be big enough for even one or two goldfish for very long. It's amazing how big those feeders can get when they don't get "fed" to others.

And the ghost shrimp are the first to disappear when anyone is the least bit agressive. And the barbs are agressive. Goldfish aren't agressive, per se, they're just gluttonous pigs, and they'll suck up the shrimp as well.

In addition, without waiting at least 4 or 5 days before adding fish to the tank, I think the only fish that will make it are the goldfish. They are the fish we use to "season" the tank for a few days to a week before adding other fish.

The fish you are proposing to buy are the least expensive part of the purchase. I think you would be better off spending the entire $50 on a good and bigger tank, and all of the supplies you will need, which can easily eat up your entire $50. Then set up the tank and let it run for about a week before going to buy your fish.

Good luck.