There are numerous places to look for aquariums for sale
First, you can check out local pet stores. While there selection is usually a bit limited, the nice thing about them is you can usually get everything you need at one place. A draw back though, is usually the sales clerks are not very knowledgeable about fishes or fish tanks. I would suggest a fish store if you can find one near by. These fish stores are starting to vanish, struggling to survive in today’s economy. If you are looking for the cheapest way to shop it would be the classified ads of your local newspaper. The draw back however is the tanks are not guaranteed and may leak so shop wisely.