One thing you will have to research is which fish are compatible with each other for your aquarium. Different fish require different water temperatures different water ph levels and the fish you choose need to eat the same types of food. Different species of fish will pray on each other when placed in the same tank, you do not want to wake up and find half of your fish are missing. One thing to consider is that marine (saltwater) fish are not as hardy as the freshwater varieties. They are also less susceptible to variations in the water temperature.

One reason that saltwater fish are less hardy than freshwater fish is the saltwater itself. All living creature whether on land or in the sea need water to survive. A fish's body requires water in order to function properly. Water is absorbed through a fish's skin in the freshwater environment. Alternatively, a saltwater fish actually has to drink the salt water, because the body fluids are extracted through the skin by osmosis. This salt is then excreted by the fish in the urine and is highly concentrated. So the saltwater fish require more care and attention and the water has to be monitored regularly. Because of this freshwater fish are a good choice for the aquarium beginner as the water specifications are easier to handle. The water temperature can vary by as much as ten degrees from the optimal temperature. For marine fish the water temperature variation usually only has about two degrees either way, far harder to keep especially in variations of room temperature.

Fish of any type are not the hardiest of creatures as regards the water temperature, water temperature is quite hard to regulate so the novice aquarium keeper can get discouraged if things do not seem right. This is where patience comes into it as some fish may not survive fluctuations of temperature. The aquarium should be set up and all the required parts thoroughly washed and in place before any fish are introduced. This includes the filtration system substrate (gravel) any decorations and plants. The aquarium filtration system should be turned on and the water temperature should be correct before introducing your fish into the tank. One of the best ways to reduce the amount of ammonia in the tank is with live plants. It is highly recommended that you use live plants in your aquarium. Live plants use the bacteria from the fish and help reduce the amount of bad chemical like ammonia in the tank. One other thing before placing the fish into the tank is to test the water for its ammonia and nitrite levels. If the levels and temperature are correct add about three to four fish only. Most fish disease or illness happen within the first month so you should keep a close eye on your first fish and wait this length of time before introducing anymore to the tank. The nitrite levels should also be reduced to zero which also takes about a month.

To keep your fish healthy there are a few basic things you should do. Firstly do not over feed the fish. Only give them enough so that it can be eaten within two to five minutes. The excess food will turn into debris and lodge in the substrate at the bottom of the tank. This can easily rot and becomes toxic to the fish as it turns into ammonia. The water in the aquarium should be changed on a regular basis. Do not change the water all at once however. At first change about twenty five percent of the water every week, making sure the water is the correct temperature when you replace it. By only partially changing the water it will cause less disruption to the fish and removes eliminates any stress that would be caused by having to remove the fish to change all of the water. The filters should be cleaned on a regular basis. Check the manufacturer’s maintenance schedule for how often this should be done as each some filters require maintenance more frequently than others.

By being patient and following just a few basic rules you should have no problem with your freshwater aquarium and it should give your great enjoyment for years to come.