SELECTING FISH
Choosing fish for your aquarium involves many decisions.
What type of aquarium do you have?
Cool water
Warm water
Size of the aquarium
Speed of growth of the fish
Aggression of the fish
Some fish will literally eat other species and cannot be kept together in an aquarium.
Appearance of fish
You may like certain fish because of their color or shape. In this case, learn about that particular type of fish, the size of aquarium it needs, what it needs, and the other types of fish it can live with.
Health
Some fish types are hardier than others.
Your best bet is to do some research on the various types of fish available. Check with a knowledgeable fish store or get a book on selecting fish.
Be careful that you don't select a species that will grow too large for your tank.
Also, don't overcrowd your aquarium with too many fish. Better to have a few happy fish than a crowded tank.
CARING FOR FISH
Your aquarium residents need proper care, just as any pet does. This includes adequate food and changing of the aquarium water.
Fish will exhibit many obvious signs of ill health, including...
Loss of appetite
Holding fins close to their bodies
Swimming fast but staying in the same spot
White spots
Sores
Gasping for oxygen near the surface of the water
Staying at the bottom of the tank
You may eventually decide to breed your fish.
PLANTS
Plants not enhance the beauty of your acrylic aquarium and create a more natural environment, they provide an important biological function.
The bacteria in your aquarium turn the fish waste into nitrites and other chemicals, and are then turned into nitrates. Plants keep the levels of nitrates low which decreases algae growth and cuts down on cleaning time. Plants thrive on the carbon dioxide that the fish produce, and the fish benefit from the oxygen produced by plants. All in all, fish and plants have a symbiotic relationship.