The size of the tank you choose will determine the number and type of fish you can keep. A good rule of thumb is one inch of fish per gallon of water but there are exceptions to this rule. The guideline of an inch of fish per gallon of water is based on a standard rectangular aquarium of normal height. If you have an unusually-shaped fish tank, such as a hexagonal, or extra high aquarium, try keeping one inch of fish for every 12 square inches (length times width) of aquarium surface area. Remember to allow for growth. The tank can be glass or acrylic and should be supported by an appropriate stand.
Filtration
There are several types of filters available the hob (hang on back), the canister, and the wet/dry or sump.
Hob filters aren’t as efficient as other types but can be used. Maintenance is easy but they can be a little noisy especially when the water level drops from evaporation.
Canisters are more efficient that hob’s but are a little harder to maintain but have the advantage of being more flexible when it comes to media choices.
Wet/dry or sump filters are more efficient that either a hob or canister. Ease of maintenance is about the same as canisters and choice of media is pretty much unlimited. They can be a tad noisy. One advantage of this type of filter is you can place the tank heaters in it thus eliminating them from the tank. Remeber you can never have too much filtration.
Filter Media
There are three basic kinds of filter media mechanical, biological, and chemical.
Mechanical media like filter pads are used to remove particles from the water.
Biological media is used to cultivate the bacteria that is used to break down waste and organic matter. Waste by nature produces ammonia, which is toxic to fish. The bacteria eventually convert this to nitrate which in small amounts is harmless to fish. The level of nitrate is controlled through water changes.
Chemical Media is used to remove or add different things to the water. One such chemical media charcoal has been used for years to remove toxins from the water but with good tank maintenance it really isn't needed. If it is not replaced often it will eventually put toxins back in the water in fact it may even be the cause of hole in the head disease.
Substrate
Substrate is pretty much personal preference I prefer gravel because I feel it's easier to clean and doesn't show waste as readily as sand. Allot of people prefer sand for the look. Rule of thumb is one pound per gallon.
Heaters
The size of the heater(s) depends on the size of the tank. Rule of thumb is 200 watt for 50gal 300 watt for anything larger. I use two in each tank in case one fails.
