Your acrylic aquarium is truly a living chemistry lab.
Like all life forms, fish produce nitrogenous waste products that break down into ammonia (NH3). This noxious byproduct must be removed because any trace of it is deadly to the fish.
In a huge sea or ocean, fish waste is negligible to the huge amount of water. But in the small, closed environment, eliminating ammonia is a major consideration to the aquarium owner.
Before adding your fish to the aquarium, the aquarium must be "cycled." That is, ammonia must be converted into nitrogen.
Start the process by introducing one or two inexpensive fish, such as goldfish, to the tank. The ammonia build-up starts soon after and bacteria will form to neutralize it into nitrogen.
Once this process has cycled, the tank is ready for your more exotic inhabitants. The cycling process can take a month or more, so don't rush it.
Test kits are available to check the water.
Ways of preventing ammonia build-up include...
It is difficult to achieve stable water chemistry in a tank smaller than 55 gallons.
