1. Fishes Only Grow To The Size Of Their Tank

People often say that fish grow to the size of their tank, but this is very untrue. Fish come in a variety of shapes and sizes. In an aquarium too small, fish tend to have stunted growth and could be suffering from health issues even though it looks like it grew to its full size. To avoid this, research the potential size of the fish you are getting before purchasing a tank. For example, fish as small as Bettas need about a 9.5 litre tank.

2. Fishes Don't Live Long

How often have you heard someone proudly say that they’ve had their fish for three or five years? Undoubtedly, this may seem like a very long time to own a fish. Most fish can will live for at least five years with a handful living for a lot longer (Goldfishes live up to 20 years). Before getting a fish it’s recommended that you do thorough research on each species you are looking you get.

Fish have different needs and have to be cared for accordingly. Low mortality rates in pet fish are often due to misinformed care by owners. With fish that live long, it is also important to plan for care in the long-term.

3. It’s Fine To Keep Fishes In Glass Bowls  

Whatever you do, do not put your fish into a glass bowl! Glass bowls are popular fish ‘tanks’ especially for fish such as Goldfish, however, they make terrible homes for them. Glass bowls are small and do not hold enough water. These bowls also have a small surface area of water compared to their volume, which means that the fish lack a larger surface area for important gas exchanges to take place.

Fishes need oxygen and glass bowls will suffocate them. Rectangular or square tanks are a better option as they have a larger surface area.

4. Water In The Tank Should Be Changed Daily

Since fishes eat and excrete in the same environment, the water in your tank is bound to get dirty. The dirt is usually bits of uneaten food, waste, or build-up of invisible waste byproducts in the form of nitrates and phosphates. An unclean tank can sicken your fish and make them susceptible to diseases. However, in desiring to keep your tank clean and your fish healthy, you shouldn’t clean your tank by changing out the water daily.

When you suddenly change all the water in the tank, it causes a shift in the makeup of the water and your fish will struggle to acclimate, eventually causing them to stress and disease before dying. Instead of changing the water daily, start by changing about 10-15 percent of the water weekly. This will allow your fish to slowly and safely adapt to the change in water chemistry.

5. A Filter Is Not Needed 

Filters are important if you want your fish to live. A filter is essential to keep your tank clean as it removes uneaten food, waste, decaying organic matter, dangerous chemicals, and floating particles. If such debris is not removed from the tank, the toxins in their waste will cause a build-up of toxins such as ammonia and nitrates in the tank, leading to ammonia stress and eventually ammonia poisoning, which is fatal.

So if you want to keep your fishies alive, a filter is a definite must.