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Rules of nature, breeding govern life in an aquarium

January 04, 2004|by ANDREA ROWLAND

A good first fish is one that's easy to feed and care for, hardy and able to live in a variety of water conditions, experienced fish-keepers said.

Captive-bred fish, including clownfish and royal grammas, are ideal starter fish for budding saltwater aquarists, said Steve Howard of the Washington (D.C.) Area Marine Aquarist Society.

Aquarist Dean Hougen suggested small schooling fish for freshwater starter tanks, including white cloud mountain minnows and some species of Danios, Rasboras and Barbs. Rainbowfish and Corydoras catfish also are ideal for beginners with larger tanks, according to an article Hougen posted on the Aquaria FAQ pages on The Krib Web site at


Schooling fish fare better amongst their own kind - so beginners should resist the temptation to mix too many species.

"In the long run, a school of a dozen fish showing their natural behavior will be more pleasing than a mixed group of fishes unhappily forced to share the same tank," Hougen wrote

He warns first-time aquarium keepers to avoid some fish, including:

  • Goldfish, which often carry diseases and parasites. In addition, all goldfish are cold water fish, which do not fare well in the lower oxygen levels found in tropical aquaria, and therefore should not be housed with tropical species.

  • Piranhas, which are easily infected with diseases and parasites from feeder fish. As schooling fish, piranhas also get stressed when kept as single specimens - but most beginners don't have a big enough tank to accommodate more than one piranha.

  • Knife fish, nocturnal predators that will feed on smaller fish in the tank.

  • Hatchet and pencil fish, which are delicate and usually require soft and acidic water. Hatchet fish also tend to launch themselves out of the aquarium.

  • Bala sharks, which outgrow most home aquaria.

  • Glass catfish, which are too delicate for beginners to handle.

Beginners also should avoid fish that have been dyed, including painted glassfish and several varieties of tetra, and fish that naturally live in brackish water, such as monos, archers and scats, Hougen wrote.

Freshwater starts

Erik Olsen, founder and editor of The Aquaria FAQ at, gave the following tips for starting a freshwater aquarium:

  • Get a bigger tank than you were thinking of getting. "Most people start with a 10-gallon, or worse, those little designer micro-tanks," Olsen said. "But those are very hard to keep stable unless you keep only a few fish. A 20-gallon tank is going to be more forgiving of mistakes like overfeeding, temperature changes and missed water changes."

  • Start with a few fish rather than loading up the entire tank at once. The aquarium's fish population should be built up slowly, two or three fish at a time. A frequently used rule of thumb is one inch of slim-bodied fish per gallon of water.

  • Get the right fish for the environment rather than trying to modify the environment for the fish. Using chemicals to change the water's pH level introduces instability to the sensitive aquatic environment.

  • Keep up on the partial water changes. Changing about 30 percent of your tank's water every other week dilutes it and removes nitrates before they accumulate to dangerous levels, and replaces trace elements and buffers that get used up by bacteria, plants and other aquarium life. Water changes are the most important step in controlling disease, Olsen said.

  • If the fish has a disease, try to identify the disease and determine what caused it before trying to medicate. The cause is often stress, and more damage can be done by randomly medicating than leaving the fish alone, he said.

Working in saltwater

The steps to starting a saltwater aquarium include:

  • Set up the aquarium and install all filtration equipment.

  • Fill the aquarium with freshwater that has ideally been treated by reverse osmosis. If you must use untreated city water, add a quality liquid dechlorinator to remove chlorine from the water.

  • Add synthetic sea salt - not table salt - by carefully following the instructions on the salt mix. Use a hydrometer to monitor and raise salinity to the desired level.

  • Install the aquarium heater and set to the desired temperature. Allow the system to run for about one week to ensure a constant water temperature and proper operation of all equipment.

  • Start building your aquarium's foundation of live rock and sand, which seeds the sand bed with beneficial bacteria and micro-organisms. Cure the live rock for four to five weeks. This process initiates the nitrogen cycle. During this time, change 25 percent of the water every week.

  • Add lighting. To combat the algae bloom that likely will follow, add an algae attack pack to your aquarium. After a few days, test the ammonia and nitrite levels.

  • Begin adding fish and invertebrates - gradually - when ammonia and nitrite levels reach "0."

- Sources: Steve Howard of the Washington (D.C.) Area Marine Aquarist Society (WAMAS) and Kevin Kohen, head of aquatic services on the Drs. Foster & Smith Veterinary Services Staff and director of the LiveAquaria Web site at Aquarist Thomas Narten also contributed much of The Aquaria FAQ's information for beginners.

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