Tank maintenance is actually easy, as long as you stick to a regular schedule. Every two weeks, about 25% of the water should be removed to get rid of some ammonia, nitrites, and nitrates in the tank. This is also a good time to scrape any algae off the tank walls and decorations. One easy way to remove water is to use a “tank vacuum” — this can be purchased at any aquarium store. As the water is siphoned off, run the vacuum over the gravel to suck out debris like uneaten food and fish droppings. When replacing the water, be sure to dechlorinate it before putting it in the tank (there are several excellent products for this purpose). Another thing you need to do is clean the filter sponge about once every 2 months. Rinse it very lightly in old tank water that has just been siphoned out to a bucket. This will remove debris that has accumulated in the filter sponge, but retain the bacteria needed for biological filtration. (Rinsing the sponge in clean chlorinated water will kill the bacteria.)
Feeding your fish is fun! But too much of a good thing can be harmful. Only feed them as much as they’ll eat in 3 minutes or so. For small fish, it’s best to feed them two small meals a day. If you’re going to be gone for up to four days, don’t place vacation feeders in the tank. Let the fish fast during that time — it’s what they do in nature anyway. They’ll be fine, and very happy to see you when you come home! It’s also good to vary the diet of your fish. Feed them a staple like fish flakes, but also supplement their diet with treats like dry or frozen bloodworms, brine shrimp, and krill.
It’s normal for all tanks to have algae. But it gets ugly when algae grows out of control. This occurs when the tank water has too much nutrients in it (from fish waste and uneaten food), and when there’s too much light in the tank. To avoid algae problems, simply adhere to a regular maintenance schedule, don’t overfeed your fish, keep your tank away from direct sunlight, and establish a day-night cycle for your tank. The day-night cycle, easily managed with a timer for your tank lights, is important for another reason: fish don’t have eyelids. In a bright tank, they will remain active, and therefore, they need darkness to rest. (If you don’t believe me, sneak up on your fish in the middle of the night with a flashlight — they’re just floating there, like astronauts asleep in the space shuttle crew deck!)
A well-maintained aquarium will keep your fish happy and healthy most of the time. But inevitably, you’ll be faced with the difficult dilemma of how to handle a sick fish. If you decide to save it, talk to an experienced fish-keeper about the symptoms, and get advice on how to medicate your fish. But if you think it would be more humane to euthanize the fish, a simple painless way to do it is to place the fish in a container with tank water, then drop a few alka-seltzer tablets in. The carbon dioxide from the tablets will put the fish to sleep, and eventually shut down its organs. (For more information on humane pet fish euthanasia, please refer to Never flush a live fish down the toilet — it’s a painful way for them to die. If you decide you no longer want to keep a particular fish, try to find it a good home with another aquarist. Some fish stores may also take unwanted fish, depending on the species and its health. But never ever release a fish into the wild because it can be potentially disruptive to the natural environment.
Well, that’s the basics for starting what I hope will be a rewarding and fun-filled hobby. There is a lot of information about fish-keeping and links to other fishkeeping-related sites at the Fish Information Service at . If you decide to delve deeper into this hobby, there are many paths to follow. You may decide to cultivate live plants in your aquarium, breed particular types of fish, perhaps set up a “biotope” tank to mimic a South American river or an African lake, maybe try salt water and reef tanks. You may even want to specialize in raising rare, endangered, or extinct (in the wild) fish, and become involved in conservation activities.
An aquarium is so much more than just a tank with fish. It’s a marvelous window into so many aspects of nature: it allows us a glimpse into the lives of fish, helps us understand the intricate balancing acts that nature does on a much grander scale, and instills in us the need to protect our fragile aquatic environment. Besides relaxing as you watch the fish go by, you can learn a lot from the little fellas with fins!