6 Best Water Clarifiers for Freshwater and Saltwater Aquariums in 2020 (Guide And Reviews)

This entry is part 3 of 3 in the series How to get crystal clear water

Your tank is cloudy so it’s hard to see your fish.

What do you do?

A few drops of a water clarifier can make all the difference. 

After using water clarifier

Your fish will be happier and so will you.

Let’s talk about water clarifiers!

1.   Important Things You Need to Know About Water Clarifiers

There are a lot of water clarifiers on the market. Choosing what to use and how to use it is important. But what is a water clarifier?

What is a water clarifier and how does it work?

Cloudy water in your fish tank is made up of tiny pieces of fish food, dust, pollen, algae and dirt.

Sometimes it’s the things that come with things you’ve put into your tank and sometimes it’s what’s around your environment. Everything in the air can affect your tank. Different times of the year, there are environmental factors that can compromise the water quality of your tank.

These little bits are so tiny. You usually would need a microscope to view them. You are not going to be able to see them on the tip of your finger.

These tiny bits will not be captured by a filter. If your tank is left untreated, it will usually get worse.

Before using water clarifier
Rainbow Aquarium Biotope Final” by  Mike S
, used under  CC BY-NC-ND 2.0  / Compressed from original

That’s where a water clarifier comes in. A water clarifier acts like glue collecting all the different bits and pieces into larger objects that your filter can grab. It’s less stressful for your fish than changing your water and cleaning the tank.

Using water clarifier

When to use it and when not?

It is important to be clear on when TO USE a water clarifier.

Poor quality tap water can have dirt and other elements in it. There can be a buildup of uneaten fish food (very common) and dust or pollen from your environment. Your gravel just might not be totally clean.

Using a water clarifier gets you back on track. It helps clean your tank without a total flush. This is better for your pet fish. It lets them stay at home while their home gets cleaned.

Equally important is to understand when you DON’T NEED to use a water clarifier.

First, check to make sure your equipment is working correctly.

Are you cleaning your tank regularly? A water clarifier is not a quick fix for this.

Are you overfeeding your fish? Using a water clarifier is introducing a something foreign into your tank so be sure you need it.

Also, algae and bacteria need a different solution.

See also:

Cloudy Goldfish Tank – The Ultimate Guide To Get Rid Of It.

Cloudy saltwater tank: The Ultimate Guide To Get Rid Of It.

How long does it take the water to clear up?


There are no fast rules on how long it’s going to take to clean up your fish tank. It depends on the size of the tank and how cloudy (dense) the problem is.

The important thing is to read the instructions on the time frame for the specific water clarifier you use. 

 Most of the time, your tank will get cloudier prior to it going clear.  

In most cases, a slow fix is the best fix as you are using the minimum amount of water clarifier which helps protect your fish. Think of going into a bath that has too much soap. It’s not going to feel good. In some cases where a water clarifier is chemically based, it could be harmful.

How to add it into your fish tank?

Rule number 1 is to read the directions.

Do the math! Make sure the amount of water clarifier is correct for your tank. That includes understanding what kind of water you have and what you have put into your fish tank before and intend to after.

Attention when using it

  • Read the instructions carefully!
  • Make sure your water clarifier is correct for your tank – freshwater or saltwater.
  • Check to make sure the water clarifier is not harmful to your specific kind of fish.
  • Check the math! Make sure you aren’t putting in too much. It could hurt your fish. Natural water clarifiers (non-chemical) are best.
  • Be patient! There is no test on how severe the problem is. It might take longer than the instructions say.
  • Choose your time to use a water clarifier. Wait at least 48 hours after using any other products and don’t introduce any for 48 hours afterwards.

What you need to do after using it?

Wait and Give it Time!

Be patient. A water clarifier isn’t going to work immediately. It has work to do. It gathers little particles into bigger objects so your filter can take care of them. The product will have estimates on how long it will take. Give it time.

Finish Up the Clean

Then, clean the filter and vacuum your gravel. Let your fish tank settle. A water clarifier clusters the tiny particles so the filter can collect things. They are now in your filter. Clean it. Some of these clusters are heavier so vacuum the gravel.

If It is Still Cloudy

If the water is still not clear, check to see how quickly you can give the tank a second dose. Read the instructions! At the same time, it is equally important to figure out the cause of the cloudy water.

2/ Products Review

NoProductsWater typeDosage
1API ACCU-CLEAR Freshwater Aquarium Water ClarifierFreshwater1ml per 10 US gallons
2>>Acurel Water Clarifier<< My PickFreshwater1ml per 10.6 US gallons
3Aqueon Water ClarifierFreshwater5ml per 10 US gallons
4Tetra WaterClarifier Treatment SolutionFreshwater1 teaspoon per 10 US gallons
5Seachem ClarityMarine&Freshwater5ml per 20 US gallons
6>>Dr Tim's Aquatics Natural Aquarium Products<< My PickSaltwater5ml per 10 US gallons

API Accu-Clear Water Clarifier


This water clarifier is for freshwater tanks only. Make sure you check the instructions for the specific dosage for your tank. It does include chemicals. Remember your tank will become cloudier before it clears. It works on most causes of cloudy water. If it doesn’t work within 24 hours, you can do a second dose.

Acurel Water Clarifier


I love this freshwater water clarifier. It’s made from organic extracts so a green product and safe for your fish and plants. It works by gathering microscopic particles into larger objects that will catch in your filter. It works within 24 hours. If your tank is still cloudy, you can dose again. Make sure you clean your filter after. Remember, it’s natural so very difficult to overdose your tank.

Aqueon Water Clarifier


The Agueon Water Clarifier is for freshwater tanks. It has a dosage cap for ensuring you have the correct amount for your tank. It works like most other clarifiers by collecting particles into bigger objects for your filter to capture. Make sure you clean or replace your filter cartridge once the tank is clear.

Tetra WaterClarifier Treatment Solution for Freshwater Aquariums


The Tetra Water Clarifier is for freshwater tanks. It is phosphate free and based on technology to clean drinking water.  It is also safe for fish in soft water. Make sure you read the instructions carefully for dosage levels.

Seachem Clarity


Seachem Clarity is a water clarifier good for both fresh and saltwater tanks. It will also clear algae and bacterical blooms. It is supposed to work within 1 to 2 hours. You can re-dose within 24 hours. Make sure you check your dosage for your specific tank.

Dr. Tim’s Aquatics Clear-UP Natural Water Clarifier – Saltwater

dr tim's-aquatics-natural-best-clarifier-for-saltwater-aquarium

Dr. Tim’s Aquatics Clear-UP Natural Water Clarifier for saltwater tanks is made up on 100% natural colloidal bacteria. With no chemicals, it is very fish friendly. Dr. Tim does add in the instructions, it is best to turn your filter off and add the Clear-UP. Turn your filter back on after about 10 to 15 minutes. It could take up to 24 hours for the tank to clear. There is also a separate product for freshwater fish tanks.

My Picks

It’s hard to argue with all-natural products. They are fish and plant friendly and I don’t have to worry about overdosing my tank. My personal picks would be Acurel Water Clarifier for freshwater tanks and Dr. Tim’s Aquatics Clear-UP Natural Water Clarifier for saltwater tanks. I would add, I was impressed that Dr. Tim has a different product for saltwater and freshwater. I can’t imagine using a product that is good for both.

3. FAQ (Frequently Asked Questions)

Why does the water become even more cloudy after using water clarifier?

As the water clarifier works, things become bigger and easier to see to the naked eye. That’s good! Just be patient and let the product do its work.

Check your instructions for how long it should take and give it a bit more time. There is no exact period the process will take. It depends on how cloudy your fish tank is.

Are there any negative effects of using it?

Depending on the product, you can overdose your tank and hurt your pet fish.

That is part of the importance of choosing a product. Natural products are better. Clear instructions on how much to use it is important. Even the type of water you have can affect how you use some products especially when they are a chemical. The recommendation is to go natural!

Is this harmful to your fish or plants?


In general, water clarifiers are safe for your pet fish and plants – as long as you use it correctly and not as a quick fix for not cleaning the tank regularly.

Make sure you read the instructions. There are some species of fish that some products should not be used in tanks. Again, check out the instructions!

How to maintain a positive fish home?

You’ve decided to have fish as pets. There are some simple rules to follow.

  • Make sure you start with a clean tank and clean material. Thoroughly rinse everything in clean water.
  • Make sure you understand what kind of water you are using. This is the home for your pets. Soft water and hard water have different issues.
  • Calcium or iron in water can affect your fish. In some cases, this might mean standing water for a period of time prior to introducing the fish into it. Sometimes, it means you need to find a different source of water.
  • Do not overstock your tank. Start with a few fish. Let them get happy and then add. But get advice on how many fish will live happily in the size of tank you have.
Do not overstock your fish tank!
  • Do not overfeed your fish. This will add to extra waste as well as uneaten food floating in the tank which can make it cloudy.
  • Make sure you carefully clean anything you add to the tank. Even things that come in packaging can have film and other chemicals on it. This can make your tank and your fish very unhappy.
  • Check your equipment regularly. Make sure the filter is working properly.
  • Protect your tank (and your fish) from direct sunlight. This can cause algae bloom which is much worse than a cloudy tank.
  • Clean your tank regularly/on a schedule. This includes washing the gravel. A happy fish lives in a clean home.

Does it work for turtle tanks?

There are water clarifiers specific to turtle tanks. Turtles can handle water a little yukkier than fish but they still like a clean home. It’s better to get a product specific to them. In many cases, simply a larger tank is better. Plus, a good cleaning schedule that you follow.

Can you use it in a fishbowl?

You can use a water clarifier in a fish bowl if you have a mechanical filtration system. But most fishbowls do not. More important is to clean the bowl, renewing the water and identifying the cause. Usually, it is overfeeding.

4. Conclusion

Water clarifiers are a great solution for cloudy water without disturbing your pet fish’s environment. But it is important to understand what caused it. Why is the water cloudy?

Checking the water quality, reviewing your feeding amounts, checking the dust and pollen in the area of your tank can all ensure you don’t get stuck fighting the cloudy water issue over and over again.  Your cleaning regime is also important. Simply changing the water is not enough. Thoroughly washing the gravel and any fixtures (castles, rocks, treasure chests, plastic and real plants) in warm water before bringing your fish home again is important. And, over-cleaning can be as troublesome as under cleaning. Disturbing the fish’s environment to often can create other issues. This is your pet fish’s home!

Have more questions or answers not found here? We’d love to hear from you.

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