fish trouble

Question
My brother got a 1/2 gallon tank the store said it was alright to have 3 goldfish 1 kissing fish and 1 snail.Its only been 4 days and all we have is the kissing fish.What happend?

Answer
Dear Collin,
What has happened is the petstore who sold you the tank and fish and gave you that advice were completely wrong.

The reason you lost most of your fish was because your aquarium is too small. This is because in that size tank, and that many fish put in at once, pollution will build up in a matter of hours. Ammonia is extremely toxic to fish even in small amounts and the buildup in a tiny tank like yours can rise to intolerable levels in one day. This is also because your new aquarium has yet to become established with special nitrifying bacteria whom convert toxic ammonia into less harmful substances. All healthy established aquariums have a good colony of these special bacteria and ammonia is never a problem.
Because a newly setup tank is completely "sterile" it cannot handle a large amount of fish. These special bacterial take patience and time to established at around 4-6 weeks.
For more information on cycling in a in-depth article- please visit-
"www.fishtanksandponds.info/setting-up/cycling/cycling.htm"
Cycling is VITAL and cannot be ignored.

Unfortunately even if your little aquarium had established a beneficial bacteria colony. The water quality would be impossible to maintain with that many fish. Goldfish are among the worst. They are well-known for being big waste producers. Not any one of the fish or snail the petstore sold you are suitable for that size aquarium. The only fish that would be suitable and even then it's on the small side would be a single Betta.

What I would really try to do now is get your remaining Kissing fish (I would imagine it's really a Kissing gourami) at least a 10gal to start out with. This is MUCH more suitable than any other size and is the most inexpensive aquarium there is. Get a simple hang-on-the-back power filter also and preferably a heater if your house is kept cold. In a 10gal trust me, it will be much easier for your to maintain this size aquarium. It will still need to cycled but this won't be too much of a hassle in a 10gal. Remember Kissing gouramis can grow to 6 inches or more and this setup is only temporary. But it's a million times better than the living conditions he is in now. If you cannot immediately get a 10gal. At the very least try to do water changes once or twice a day on your 1/2 gallon. Take the water down to just enough to cover the Gourami and gently fill it back up with fresh conditioned tap water. *You MUST insure the replacement water is equal in temperature (by checking with an aquarium thermometer) and dechlorinated with a good water conditioner at every water change. Continue these water changes everyday. Use a water conditioner if you can that neutralizes or removes ammonia such as Prime or Amquel. Adding "Zeolite" can remove ammonia as well and help matters but above all try to get a larger aquarium soon!

I'm sorry to say your Kissing gourami is likely suffering from poor water quality and he may be too far gone if the conditions aren't improved soon.

I'm also very sorry you were the victim of another petstore's misinformation. On all the time i've been volunteering on allexperts, This has happened so many times before I have lost count. What makes me feel so sad is why the petstore couldn't have told you the same thing I've told you. But it's true that many petstores care more about the sale than the health and well-being of their fish.

I really hope this helps and if you have anymore questions or concerns, feel free to write.
Best wishes,
Karen~