How Do You Keep Your Aquarium Water Crystal Clear

So, you purchased an aquarium and all of the extras; lights, filters, rocks, plants, testing strips, fish, and fish food. Now what? You want to set-up the aquarium and have everything done correctly so that your fish will last longer and won’t get sick. One of the biggest things to accomplish this is having crystal clear water.

Crystal clear aquarium water will prolong the life of your fish, the live plants that you place in the tank, and it will be more appealing to friends and family to look at when they come over to visit.

How do you keep your aquarium water crystal clear? It starts from the initial set-up of your tank. The more live plants you put in the tank, the better. But do not make it so cramped that the fish can not swim around and you can’t see/enjoy your fish. Plants have microbes and bacteria on them. This helps begin the “balance” in the aquarium. The cloudy water will begin to go away on its own in 7-10 days. After that, you just need to keep good maintenance and it will stay crystal clear. 

We will explain why your tank water turns cloudy/milky during the first week or so after you set it all up. I will also provide you with things you don’t want to do to try to fix the cloudy water.

I will also offer some tips, tricks, and products that will help you achieve and maintain your crystal clear oasis. Before you actually purchase anything to assist in keeping the water crystal clear, read the directions carefully. Make sure it is not going to be harmful to the live plants that you place in the tank. 

Why Is Water Milky/Cloudy?

When you set-up your aquarium for the first time, you are going to have what is referred to as “new tank syndrome”. Your aquarium is full of living organisms; bacteria, protozoa, and others. They come from the fish waste, food, and the fish themselves. 

The good news!? Even though it doesn’t look healthy and you are chomping at the bit to fix it, leave it be. The milkiness will go away on its own, once the tank begins to balance out all of the organisms causing the issue. Just be patient, maybe ease up on the feedings, and see where you stand in about 7-10 days after you set-up your tank.

If you add good bacteria to the water, it will help achieve the balance in the aquarium. Purchase gravel that already has bacteria on it or you can also buy pre-packaged bacteria. If you already have a well established tank you can take just a couple of the decorations out and put them in the new tank. They already have the good bacteria established.

When you are purchasing plants for your aquarium make sure they are live plants. Fake plants are often made of plastic and have a weird coating on them. The live plants will help in reducing the nitrate levels in the aquarium. You want to also make sure that you purchase the correct filtration system for your tank and the species of fish that you will have in the tank.

To help get rid of and prevent cloudy water you want to maintain your aquarium. Pick a day each week, for the first month, and replace 20%-25% of the water in the tank. Make sure that you let the new water sit in a bowl for up to 48 hours. This will get it to room temperature so it is less likely to shock the fish (by being too warm or too cold). It will also help settle the pH from any chemicals that you add to the water.

In order to have and keep crystal clear aquarium water you also need to keep your filter clean. Check them weekly for blockage and clean as needed. DO NOT rinse the cartridge. That will remove the bacteria which will then raise the ammonia and nitrite levels. Instead, use tweezers to remove the items and fish waste that are causing the blockage in the filter.

Things NOT to Do

One of the biggest no-no’s in trying to fix a cloudy tank issue is changing the filtration system or the filter. Cleaning a brand new filter hinders the growth of the good bacteria. If your filter or filter pad needs to be replaced more than once a month it means you have overstocked your tank with fish or you are feeding them too much too often, or both.

You should only feed your fish what they can eat in 2 minutes. The rest of the food just falls to the bottom of the tank and aids in the cloudy water situation.

Do not change the water (20-25%) more than once a week, during the ‘new tank syndrome’. After that you can move your cleanings to once a month (doing a full tank water exchange every couple of months). If you change the water more than once a week you are fueling the cloudiness because you are providing a spike in nutrients with every water change. 

Some Other Helpful Tips for Crystal Clear Water

  1. Don’t overfeed your fish. Depending on the type of fish you have in your aquarium, you only feed them every other day or 3-4 times a week.
  1. Do not put too many fish in your aquarium. The more fish you have the more water and microbes you have, which are 2 of the leading things that cause the cloudy water. It will also cause a rise in nitrites and ammonia which would be very harmful to the fish.
  1. DO add carbon pads or carbon media to the filter. This will assist in helping the water stay crystal clear. It will also absorb all of the nutrients that feed the bacteria. 

Products That Can Assist You and Maintain the Crystal Clear Water

CarbonCarbon is one of the best and highly recommended products to use to keep your aquarium water crystal clear. Carbon absorbs odors and dyes that contribute to cloudy water.
Accu-ClearAccu-Clear is an aquarium water clarifier. It will help maximize your filter efficiency, it clumps floating particles together, and it is safe to use once a week when you do your maintenance. 
KloudAwayKloudAway is also an aquarium water clarifier that is fast-acting, targets unwanted particles in the water; fish food, dust, and other debris. It clumps them together so that they are easier to remove from the tank.
Acurel Water ClarifierAcurel Water Clarifier is safe for both fish and live plants, helps rid your tank of cloudy, green, and polluted water.
Aqueon Water ClarifierAqueon Water Clarifier After usage you need to do your weekly maintenance to remove any particles that are on the bottom of the tank. It is safe for all fish and lives plants in both fresh and saltwater. It clings to the floating dust particles that cause cloudy water.


To have healthy, happy fish that will live longer you want to make sure that after the ‘new tank syndrome’ you keep your water as crystal clear as possible. There are many ways, as we have described above, to help you achieve this.

Before using any products read the directions carefully and use only as directed. Remember to do a 20% to 25% water change once a week and just be patient, the cloudy water will go away in 7-10 days. 


I'm passionate about fish pets and love sharing everything I learn about them.

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