You’ve just bought a brand new aquarium and set it up. Only a few days have passed since you cleaned it and you noticed that the water is now cloudy. You’re probably worried and asking yourself where you went wrong – but don’t worry. 90% of the time, cloudy aquarium water is only a temporary problem which is easy to solve. In this article, we reveal how.

Why is my aquarium water cloudy?

Contrary to popular belief, cloudy aquarium water is rarely related to dirt within the aquarium. Cloudy aquarium water occurs for multiple reasons. Below are some of the most common ones:

1) Bacteria bloom

If you’ve just set up a brand new aquarium, cloudy water is completely normal. There is a a certain amount of healthy bacteria in all aquarium water. Once you set up a new aquarium, these bacteria will begin multiplying, and will require a certain amount of time to stabilize. If you notice milky, cloudy aquarium water, this could just be an explosion of nitrifying bacteria. But don’t worry, the bacteria problem will be resolved within a matter of days on its own – excess bacteria will die off in time and their numbers will stabilize. It’s essential that you remain patient and don’t tamper with your aquarium water in this stage.

2) You didn’t wash the gravel properly

Sometimes, gravel needs to be cleaned extremely thoroughly. Most first-timers make the mistake of rinsing gravel only once or twice. Sometimes, you’ll have to rinse your gravel up to 30 times to get completely rid of dust and debris! Put the gravel in a bucket, and make sure to mix and shake it with your hands until the water turns cloudy. Empty the water and repeat. This process needs to be repeated until the water turns crystal clear – which could take a while, depending on the gravel. Thankfully, it only needs to be done once if done properly.

3) Tannins

If your aquarium is home to driftwood, and your water has gotten a brown/yellow-ish tint to it, tannic acid is the most likely cause. Although tannins are very healthy for the chemistry of your aquarium, they can cause your aquarium to appear dirty. You can prevent this from happening by thoroughly boiling any driftwood before adding it to your aquarium. Ideally, you should be boiling the driftwood multiple times until the water is clean and stops changing color.

4) Overfeeding

It’s crucial not to overfeed your fish. The more food is present, the more your fish will produce waste products, which can pollute the water and make it turn cloudy. A good rule of thumb is to never throw in more food than your fish can consume within two minutes.

5) Tap water

Depending on where you live, your tap water may not be of ideal quality. Before you fill your aquarium with water, it would be beneficial to test it’s hardness. Heavy calcium buildup can cause a “milky” appearance in your aquarium water.

In certain cases, an aquarium water clarifier could be of great help to keep your water pure and crystal-clear. The way most clarifiers work is by binding extremely tiny particles together – which allows them to be captured in your filter’s mechanical media. While it won’t help with bacteria blooms, a clarifier is a great option if you didn’t rinse your gravel properly.