Goldfishes are popular among aquarists. They are beautiful and great to keep in an aquarium but we hate to break it to you – they are not the best starter fish for beginners as they are often made out to be. The reasons for this are as follows:
1. They will grow into their adult size eventually
In most cases, people keep goldfish in a small bowl or a small tank and the size they will grow into is often ignored. A bowl or a small tank is too small for their needs. Goldfish need at least 50 litres individually and they do not like to be alone so you will need at least 150 litres for a bunch of them. They will seem small when you see them in a pet shop but they can actually grow up to 15 inches or more. A popular misconception is that they will adapt to the size of the bowl or tank. A tank that is not suitable for them will result in stunted growth and your fish will eventually die because its organs, fins, etc. will keep on growing and the bowl or small tank won’t be able to accommodate the goldfish anymore.
PRO TIP # 1
If you provide a decent space to a young goldfish, they can grow to 4-5 inches in a year’s time.
2. They produce a lot of waste
Goldfish produce a lot of waste as compared to other species of starter fish which have a lot of bio load. This is another reason why they should be kept in a properly sized aquarium as a lot of waste in the tank will pollute the tank and cause an ammonia spike. Their skin, fins and gills could burn from the ammonia that they will produce. It can cause many diseases and even death.
PRO TIP # 2
Do a weekly water change of 25-50% depending on the capacity and no. of goldfish in your tank and use ‘AQUATIC VENTUREZ Purify Media’ to control ammonia spike.

3. They have specialised needs
They have specialised tank requirements. Goldfish need a lot of oxygen to thrive and live long happy lives. At the surface level of water, water and air undergo an exchange of gases- oxygen from the air goes into the water and carbon dioxide is released from the water which goes into the air. This is how fishes get their oxygen. Goldfish need oxygen from the surface of the water which means you will need a tank with enough surface area and water agitation which will ensure the exchange of gases and give them the much needed copious amounts of oxygen. This is why small tanks and bowls are not suitable for goldfish. If you notice that your goldfishes are constantly at the surface, it means that they are gasping for air.
PRO TIP # 3
Have a powerful filter i.e. at least 6x times the aquarium capacity. For example, if the tank capacity is 100 litres, then the filtration capacity should be at least 600 litres per hour.
- They need a large tank or a pond
Smaller tanks and bowls undergo fluctuating water chemistry; they have bigger effects and changes in the water parameters whereas large tanks are easier to maintain and the water chemistry remains stable. Goldfish need at least 50 litres individually and they do not like to be alone so you will need around 150 litres for a bunch of them. It is best to have a tank twice the recommended size and many beginner aquarists are not ready for that. Moreover, your tank needs adequate aeration and filtration to encourage the growth of beneficial bacteria that will counterbalance the levels of ammonia in the water.
Goldfishes are a great responsibility that beginner aquarists may not be ready for yet. With proper care, good filtration, regular maintenance, knowledge, and a properly sized tank, they can live long and happy lives. Hence, consider the above points before you introduce a goldfish in your new tank.
This article is contributed by Aquariums India which is the first and largest online store for aquarium products based out of Kolkata since 2006.