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Does Cloudy Water in a Tank Kill the Fish?

Will Cloudy Water Kill Aquarium Fish San Diego, CA

Clear water is an important goal for all aquarium keepers. This is a concept that ties into the human preference for clear water to drink and swim in. We don’t even think about cloudy water coming out of the shower when we bathe, and we certainly don’t want to see H2O that doesn’t provide a clear view of the fish species we keep. In some cases, cloudy water can be harmful to fish, but not all the time. Here’s what you need to know about cloudy water in an aquarium.

Cloudy Water Often Occurs in a New Aquarium

There’s a break-in period for all new aquariums, and this is when most aquarists will see the first instance of cloudy water. It typically happens not long after introducing the first fish and plant species, and it’s related to a beneficial bacterial bloom. which is normal. As with all ecosystems, bacteria is required to keep things biologically calibrated and balanced. The species in your tank will take care of the rest and the water will clear up after a few days as long as you have a proper filtration system in place and the right mix of chemicals. Also, it’s very important to not overfeed your fish. At Aquatic Warehouse, we call this need to feed “loving your fish to death.”

When Cloudiness Persists After a Week

If you notice cloudy water remains, or if it returns with a thicker haze after having cleared up, you may need to test the water and determine what could be wrong. Keep in mind that many freshwater aquarium species are very resilient. Some of them may even enjoy swimming in cloudy water if they’re native to brackish water habitats. The initial bacterial bloom looks like a fog or mist. If it starts turning brown or green, you may be looking at algae bloom that could be harmful to some species.

Proper Filtration Is Key

Fish and plants do their biological parts to keep things clear. The rest is up to you. Mechanical filtration systems simulate currents that keep debris and some microorganisms on the move, which is necessary for a healthy aquarium. The size of the filters is crucial in this case. Investing in a larger and finer filter is always recommended. There’s also chemical filtration to consider, and activated carbon is one of the best options in this regard.

Testing the Water

If you don’t have a testing kit for ammonia and nitrates, collect a small sample in a bottle or container you can take to your local aquarium supplier. Make a list of the species you have or take pictures with your smartphone. Don’t wait too long to get the water tested or to apply remedies. The health of your fish could depend on how quickly and effectively you can clear up the water.

Whether you’re having difficulty clearing the water in your tank or need advice on other common issues aquarists face, reach out to the aquarium experts at Aquatic Warehouse. We are a leading provider of saltwater and freshwater aquarium supplies and pond equipment. Give one of our knowledgeable representatives a call today at 858-467-9297.




Contact Information

  • Address: 5466 Complex Street Suite 204
    San Diego, CA 92123
  • Phone: (858) 467-9297
  • Email: sales@aquaticwarehouse.com
  • Working Days/Hours: Mon - Fri / 10:00 AM - 7:00 PM
    Saturday / 10:00 AM - 6:00 PM
    Sunday / 11:00 AM - 6:00 PM


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