How to Fix Cloudy Aquarium Water?


How to Fix Cloudy Aquarium Water?

Many people usually find pleasure in keeping pets in their houses for various reasons. Some people keep fish for fun, while others for bringing a piece of nature into their home.

Keeping aquarium fish also usually come with responsibilities and issues. One of the most common issue in the aquarium hobby is cloudy aquarium water.

The water of a healthy aquarium should be clean and see-through. If the water of the aquarium gets cloudy, it is an indication that something is wrong.

In most of the cases cloudy aquarium water is caused by too much light, overfeeding, excess of nutrients in the water column, overstocking or lack of maintenance.

Cloudy water is common in new aquariums, but established aquariums can also have this issue due to lack of aquarium maintenance.

How to Take Care of Your Aquarium?

Monthly Care

  • Remove all algae you can from glass and aquarium decoration (it is fine if there is some left)
  • Prune live plants if necessary and remove all dead leaves or decaying plant matter
  • Have an inspection on the filter, clean or replace the cartridges.
  • Clean the gravel with a gravel vacuum
  • Clean or replace the airstone if necessary

Weekly Care

  • Scrub the algae that is built on the glass
  • Replace 10-30% of the tank water with clear water (use a water conditioner such as Seachem Pirme to remove chlorine and chemicals from the water)
  • Clean the filter is necessary
  • Inspect the fish for any diseases or parasites

Daily Care

  • Ensure that temperature is stable, equipment is working and fish a fed.

Chemicals Present in Aquarium

Chloramines and Chlorine

  • These are in most cases found in the water city and therefore, for the sake of fish should be removed.
  • Tap water also contains chlorine hence makes the water to be toxic to fish. The use of de-chlorinator can, however, be used to wash any water that should be replenished to the aquarium.

Nitrite: In many cases, the nitrite usually levels down oxygen in the blood of fish.

Alkalinity: It usually levels up the water alkalinity to stabilize the level of Ph

Hardness: The hardness can be described as the level of magnesium and calcium inside the water. A test of the hardness of the water is, therefore, needed before any changes in the water is made.

Aquarium Filtration Types

The most common types of filtration are usually 3 in number, and these are; chemical, biological, and mechanical.

Naturally, it is a prerequisite that all the three types to be employed since they help in neutralization of nitrites, ammonia, and the removal of contaminants.

The 3 standard methods are usually put in use are:

  • Canister filter: This is the most appropriate for aquariums that can hold up to 55 gallons or even more
  • Power filter: This is almost the same as canisters since it also holds s55gallons. It can, however, be mixed with under-gravel screen for many fish.
  • External power filter: This is situated at the back of the aquarium. This kind usually pumps water to the replaceable tank.

Types of Aquariums

  • Brackish Aquarium

This type contains a combination of fresh and saltwater.

Many people find it difficult to sustain this kind because the water conditions are not easy to maintain.

The facts that the fish that are brackish have not been adequately housed before they get to aquarium also make it not to be appealing to many.

  • Cold Water Aquarium

The temperature in this kind is usually less than 70 degrees or instead room temperatures that are in many homes.

The Goldfish is among the most common types of fish that are housed in this kind of aquariums.

The Goldfish and Koi ponds are some of the best examples of domesticated habitats for coldwater fish.

  • Marine Aquariums

One of the prerequisites of the marine tanks is saltwater; this helps the fish for survival.

Salt is, therefore, bought and mixed so that it can be added to the tank.

The marine aquarium is, in most cases considered in terms of cost because of its nature to keep coral.

Causes of Cloudy Aquarium Water

Gravel that has not been appropriately rinsed may cause cloudiness in a new aquarium.

Likewise, when filters are restarted following a shutdown, they usually result in minute debris plus some tiny bubbles of air which ends up creating a whitish coat.

An act of adding calcium, ph adjusters, and bacterial tends to supplements the temporal milky coat in the water.

The white cloudiness is never permanent but usually takes some hours or days before they disappear.

There are, however, some points where the cloudiness may continue growing in place of disappearing.

Whenever such take place, then there are high chances that some bacteria have caused it.

Besides, you may at some point see some temporal unpleasant green water that in most cases shows up in the aquarium.

This is always a sequel of (algae) bloom.

An alga is a form of watery plant life with numerous species almost amounting to 10,000.

The algae build up energy plus growth by the process of light photosynthesis.

The freshwater green algae usually form in the fish tanks.

Actual Causes of Cloudy Water

  • Excess Food

The leftovers, a result of overfeeding become the nutrients for the growth of the algae.

  • Too much light

Excess light can be formed from the direct sunlight, which ends up photosynthesizing.

As a result, the algae in the aquarium blossoms because of the direct sunlight.

  • A large number of fish

The presence of too many fish also increases waste organic that provides nutrients for plants.

Cures for Cloudy Aquarium Water

  • Provide crustaceans such as daphnia to eat the algae, and these are in turn fed on by the fish.
  • If possible, it’s advisable to provide a blockage to light because this completely cut up the photosynthesis process which supports the growth of algae.
  • To remove the algae that are suspended in the water, installation of micron filtration system should be done
  • Avoid the transition of significant rain, and this is because the water changes can effectively affect the aquarium balance leading to the deterioration of the quality.
  • Patience is required. The reason for patience here is to give ample time to balance and recover the excellent condition that was once there.

It’s after ensuring that the aquarium is spotlessly clean and healthy for the fish, which the fixing step chips in.

Steps of Fixing Cloudy Aquarium Water

  • Step 1: disconnect any electrical equipment such as heater, filter and lights before you put your hands in the aquarium
  • Step 2: remove aquarium decorations such as rocks, plastic plants or other decorations and place them on a paper towel.
  • Step 3: scrub the algae off from the aquarium glass and the decorations you’ve removed
  • Step 4: start cleaning the gravel or substrate with a grave vacuum – don’t remove more than 50% of the water
  • Step 5: clean the filter by rinsing the sponges and filter media in aquarium water (do not use tap water because chlorine will kill off beneficial bacteria)
  • Step 6: top off your aquarium with fresh water (don’t forget to use a water conditioner such as Seachem Prime to remove chlorine and other chemicals)
  • Step 7: put back the rocks and decorations into your fish tank
  • Step 8: reinstall the heater, filter and lights (make sure the filter is doing its job properly)
  • Step 10: add beneficial bacteria to the aquarium in order to speed up the clearing process – I highly recommend Seachem Stability

Fish can survive without food for days, some for even weeks. Do not feed them very much in the next few days. This will help in establishing the aquarium much faster. If the aquarium is still cloudy, you need to repeat the process after one week.


Cloudy water has posed a challenge to many aquarists, especially those that are new to the hobby.

Though, this can be fixed easily, just need some work and patience.

With the above steps, you can solve the cloud aquarium water with a week or two.

If you might have other issues regarding fish keeping or aquarium maintenance, please check out my other articles or leave a comment below.

Fishkeeping   Updated: November 5, 2020
avatar Hello, my name is Fabian, and I am the Chief Editor at Aquarium Nexus. I have over 20 years of experience in keeping and breeding fish. The aquarium hobby brings me immense joy, and I take great pleasure in sharing my experiences with others.

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