Secret Guide - How To Get Crystal Clear Aquarium Water

Secret Guide - How To Get Crystal Clear Aquarium Water

Guide To Clear Aquarium Water

Everyone wants clear aquarium water, period. For the new aquarium owner, it might seem like a difficult task that requires a ton of work and advanced knowledge of aquatic ecosystems. Luckily, it DOES NOT! Today we will cover several tips and strategies that will help clear up your water and will result in a stunning crystal clear aquarium. Lets begin discussing the different causes of cloudy or discolored tank water and then move on to how you can fix it. 

Why Is My Aquarium Water Cloudy?

Algae Blooms (green water)

Algae blooms such as green water may occur in new aquariums, or tanks that have a large disruption in their water chemistry. There are several causes for green water algal blooms, most of which can easily be avoided.  Too much light paired with high phosphates as a result of over feeding is likely the cause. Green water is not a threat to any of your aquarium inhabitants, but it is unsightly.

Bacterial Blooms (grey/white hazy water

Cloudy water is most often caused by bacterial blooms. Several different types of bacterial and other microbes are always present in your aquarium, it's when one of them get's out of control and replicates uncontrollably that problems can arise. Luckily, bacterial blooms are often short lived and will resolve themselves after a few days to to few weeks. There is typically no need to worry about a bacterial bloom as they should not harm any of your fish or invertebrates. If a bloom lasts for an extended period of time and does not resolve itself naturally, check you nitrogen water parameters (NH3/NO2-/NO3-) to make sure there isn't a more serious issue.  

Dissolved Organic Carbon (tea colored water) 

There are lots of organic substances in your aquarium that will not affect the water clarity. Substances called tannis are dissolved organic compounds often leached out of driftwood, leaves and seed pods. Many hobbiests intentionally add these components to create a more natural aquarium; some tannins actually have anti-bacterial and other beneficial properties.  New aquarium owners may be confused when they set up a new tank with common drift wood or soil substrate only to see dark tea colored water the next day. Cloudy water caused by natural tannins is not harmful to your fish or any other inhabitants.   

Inorganic Substances / Particulates (grey/brown hazy water)  

Probably the least likely cause of your hazy or cloudy water, certain inorganics can cause aquarium water to be less clear. High concentrations of phosphates (PO4) as well as dissolved minerals (very hard water, silicates, Iron, etc.) can prevent a fish tank from looking crystal clear. Material such as microscopic clay particles that stay suspended in the water may also contribute to discolored, hazy tank water.  Now that we have a good understanding of how aquarium water can become cloudy or turbid, lets talk about ways to correct the problems. 

How To Get Crystal Clear Aquarium Water

There is often a unique solution to resolving your aquariums cloudy or discolored water depending on what is causing it. Hopefully the above information has helped you narrowed it down. Now I'll discuss a few different tactics you can use to help remedy the situation. 

6 Easy Tips To Prevent Cloudy Fish Tank Water

Aquarium Plants

While just having a planted aquarium will not always prevent you from having issues with cloudy or discolored fish tank water, plants can help a tremendous amount with multiple aspects of you tank. Actively growing plants will consume both harmful and safe compounds like ammonia and Iron which can cause bacterial and algal blooms. Having lots of healthy aquarium plants will help prevent your aquariums environment from becoming unstable, another reason for a sporadic algal of bacterial bloom.  Here is a list of aquarium plants that I highly recommend.


When it comes to filtration, you can never over do it. As long as the flow isn't blowing around your fish and plants too much, a larger more powerful filter will never be a bad thing. Having to little filtration in an unbalanced tank can create an opportunity for excess waste and or certain bacteria to increase and cause cloudy water. Furthermore, not having the proper mechanical filtration in your filter can prevent its ability to sift our fine particles that may be contributing to the discolored water. Using a fine filter pad or even better, a poly filter floss will catch all the tiny free floating particles looming in your tank water. Having robust filtration will also help process more waste and help to keep your fish tank clean and safe for all your inhabitants.  

Don't Over Feed

Adding to much fish food to your aquarium can have several negative effects on the overall aquatic system. Ammonia spikes are often a result of over feeding in a new tank that is not fully established with beneficial bacteria. Ammonia itself can also be a contributing factor in bacterial blooms even if you can't detect it with traditional test kits. Less food = less waste = less cloudy water issues.

Clean Up Crew

Having a reliable clean up crew is one of the best natural ways to help prevent cloudy fish tank water. Amano Shrimp, Siamese Algae Eaters, Nerite Snails and Otto Cats are all members of my favorite clean up crews for freshwater aquariums. These fish and invertebrate all work independently to consume waste and even excess algae resulting in an overall cleaner aquarium.  A good clean up crew can help consume left over fish food that if left to build up in the aquarium can result in bacterial and algal blooms.   

Activated Carbon

Activated carbon is a material that all experienced aquarium owners know about. Many of the filters you purchases come with some form of it. To simplify, activated carbon is a bed of charged particles that will physically bind other particles of opposite charge once they pass though the filter. Adding carbon to your filter will help remove substances and waste products like large tannins and medications. Also called activated charcoal, it can also help to reduce unpleasant smells you may have coming from your aquarium.  


There are many chemical agents available that will quickly resolve many of your cloudy water aquarium problems. Also referred to as floucculating agents, these liquid solutions will bind to bacteria, algae and other physical debris in your tank that might be causing cloudy water and force them to drop to the bottom of the tank or be captured in the filter. I always recommend you try and solve the problem naturally at first, but using a clarifiers has worked well for me in the past. Using any type of band-aid solution such as a chemical additive like an algaecide will often solve the problem initially, but can quickly rebound if the root of the issue is not taken care of. When it comes to discolored tank water I have had several experiences where adding a clarifyer solved the problem and it did not return, therefor I do recommend Fritz Clarifier if you cant seem to solve the problem. 

Fritz Clarifier

Safe for all aquarium inhabitants, this easy to use flocculationg agent that will clear up your cloudy water problems in less than an hour! 

Just Wait...

Many times, certain causes of cloudy aquarium water will resolve naturally with time. Most of the time cloudy or discolored water is caused by a bacterial bloom which occurs when something that is normally limited, becomes available (extra waste, particular nutrient, etc.). The microbes will take advantage, consume it and grow to high numbers. Eventually, that once limited nutrient we be completely consumed and the bacterial colony will collapse.  If the cloudiness persists for more than a week or so, you will want to take some additional steps that I've already mentioned above. 

Commonly Asked Questions About Cloudy Fish tank Water:

My tank is only a few days old and it already has a grey/white cloudiness to it, what's wrong?  New aquariums that have not properly finished it's beneficial bacteria cycle, are often susceptible to bacterial blooms. Make sure to add in a culture of nitrifying bacteria or seed your new filter with established media from an existing aquarium to prevent other unwanted bacteria from taking over. 

My aquarium randomly became cloudy, should I do a big water change? Yes, but don't over do it. If you aquarium is established and this is purely a random event, try a 50% water change and wait a few days. As long as you don't suspect an ammonia (NH3) spike (you can certainly check) then give the tank some time to adjust. Many times bacterial blooms will naturally resolve them selves when the bloom consumes all of the factor which allowed them to proliferate in the first place.  

Is there a natural way to fix cloudy water in my aquarium? There are a few different methods that work well. I like to start with more frequent water changes (twice a week). If the problem continues, re-evaluate my system- Do I have a good clean up crew? Do I have activated carbon in my filter? Have I been feeding to much/often? Addressing those few thinks will typically solve the problem fast. 

I used a clarifying agent but the cloudiness came back, what now? If the clarifier did not permanently solve the problem, now its time to diagnose the route of the issue. It could be that more time needs to pass to naturally resolve, never forget that! Add an extra water change into your normal routine and make sure your haven't been feeding to much or have an Ammonia spike or high levels of Nitrate or Phosphate. 

What is the most common cause of cloudy aquarium water? In my opinion, bacterial blooms are the most common cause of discolored or cloudy fish tanks. There are several factors that can easily change to allow bacterial to proliferate. 

I think excess phosphates are causing my cloudiness, how can I prevent this? Take a look at what you are feeding, is it high in phosphates / phosphorus?  Are you feeding excessively to a large number of fish? If you tank is lightly planted or not planted at all, a phosphate removing media like Maxout Pro Freshwater can help resolve the issue.

What's the best way to prevent cloudy water in my fish tank? Balance, balance and more balance.   

Other Algae Fighting Products

Cyanobacteria Remover

Aquarium safe powder that will remove blue-green algae/cyanobacteria in a few days!


Fritz Clean Out

Fish safe algae removal product to help get rid of various types of algae that may be contributing to cloudy aquarium water.

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Already more then 6 months water still cloudy


My tank already more than 6 months, cloudy water still appears.Even changed my water every 3 days to 50%


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