When should the water in an aquarium be changed?

When should the water in an aquarium be changed?

Changing the water in an aquarium is essential to keep its fish healthy. It also allows the water to remain healthy and toxic chemicals, such as ammonia and nitrites, to disappear. Because even if your water seems clear, you may be surprised by the amount of debris present at the bottom of the tank. Read this article to find out when to change the water in your aquarium!

Why change the water in your aquarium?

There are two reasons why changing the water in an aquarium is essential. First, it eliminates nitrates and phosphates. In addition to the debris you can see with the naked eye, other invisible natural waste accumulates in the water. They are called nitrates and phosphates. These elements are harmful to fish as they make them more susceptible to disease. In addition, they can stunt the growth of young fish and harm the reproduction of adult animals.

Regular water changes will also allow you to rebalance certain trace elements that have been depleted over time. Indeed, plants, fish and invertebrates consume certain trace elements such as calcium, potassium, iron, etc. Thus, the change of water in the aquarium will allow the fauna and flora of your aquarium to obtain the foodstuffs they need.

Should you change the water in your aquarium every week?

Changing the water in your aquarium every week is an excellent idea to avoid sudden variations. Of course, the frequency can vary depending on the size, population and configuration of the aquarium. As a general rule, small aquariums with large populations require more regular water changes.

Either way, you will need to invest time in renewing your aquarium water. Performing a thorough cleaning once a month is not enough. In four weeks, the impurities have time to become embedded and affect the health of your fish.

How much water in your aquarium should you change?

You should never change 100% of your aquarium at once! We now know that this method is likely to cause stress in marine animals. Experienced aquarists agree that it is best to change a small portion of the tank water as often as possible. Thus, this partial change does not disturb the balance of the fish.

For a classic maintenance, it is therefore preferable to change a small quantity of water. The rule is therefore to change 5 to 10% of the water in your aquarium every week. If your aquarium is heavily populated, it may be a good idea to increase this percentage to 15 or 20%. But if you want to get a very precise indication, testing the nitrate level of your aquarium is the best solution, especially when you are new to aquariums.

With that in mind, invest in a nitrate (NO3) test. Then, try to keep your aquarium's nitrate level within the following range: 10 to 20 mg/L. As long as your aquarium's nitrate level remains between 10 to 20 mg/L, perform small weekly water changes. On the contrary, switch to larger water changes if your nitrate level exceeds 20 mg/L.

How to perform a nitrate test in an aquarium?

Although nitrate is not as toxic as ammonia or nitrite, its levels should be monitored to avoid stress to fish.

To carry out a nitrate test in an aquarium, you will need to equip yourself with the appropriate equipment. If you are just starting out and have a limited budget, we recommend test strips. This is an affordable, simple and fast solution since it only takes 60 seconds to obtain the result of 5 parameters simultaneously.

But for greater accuracy, droplet colorimetric tests are more widely used by experienced aquarists. To use this test, you will fill a small vial with your aquarium water. Then you will add a small reagent. Depending on the color of the water, you can precisely define the nitrate level of your aquarium.

Our latest tips to make changing the water in your aquarium easier

If there was one thing to remember from this article, it is that the water in your aquarium should be changed in small quantities (about 10%) regularly. This is how you can ensure that the fish in your aquarium stay thriving and healthy.

To make it easier to change the water in your aquarium, place a marker in one corner of the tank. This way, you can easily change the same amount of water each time. Finally, note that the water temperature should be the same as that already present in the aquarium, or even slightly lower.

And for even more aquarium-related tips and tricks, browse our blog!