How to Remove Silica From Aquarium Water

Silica is a mineral that occurs naturally in freshwater and saltwater. It can be found in the form of sand, pebbles, or rocks. While it’s not toxic to your fish or invertebrates, silica buildup can cause problems with water quality over time. This post will teach you how to remove silica from aquarium water when it gets out of balance. 

Silica From Aquarium Water

The most common way to control the buildup is through regular partial water changes. However, it would help if you also used activated carbon filters for any new tap water that enters the system. This removes many pollutants, including silicates which are known contributors to high levels of dissolved solids in aquariums.

Step to Follow on How to Remove Silica From Aquarium Water

Step One: Determine

First, you want to determine how much silica exists in your aquarium water before taking any action. To do this, you need a test kit that will measure the amount of silicate present. There are many brands available, and which one you choose depends on personal preference or what can be bought locally.

Measure Silicate Amount

Sachems kits are top-rated and easy to use. They work the same way; the only difference is which one was made by who. The first step is to take your water sample and pour it into the container that comes with the kit. It should contain three small containers; two will already have an agent in them for you to add water to.

The other should have a little white strip of paper. This paper usually has either a color spot on one end or multiple dots. You will need to compare the color on the paper after it has been soaked in the sample for 1-2 minutes. The color should be yellow, green, or pink indicating how much silicate is present.

Step Two: Buy Supplies

Once you know how much silicate is in the aquarium water, you can start going out and buying supplies to remove it. First, make sure you buy a good quality carbon that will filter out silicate. The best type of carbon to use is a mixture of both active and granular carbon.

Many brands are available, but I do not recommend buying the cheapest version because it will work very poorly. A good quality carbon that works very well is the Seachem Matrix Carbon. It has a high affinity for silicate and reduces it by about 90%.

Using a reverse osmosis unit is another way to help lower the amount of silicate available in your aquarium water. These units remove many different chemicals from tap water, including silica. However, they also take out other minerals and should be used with caution as you need those to keep your fish healthy.

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Step Three: Use Equipment

Once you have your carbon or RO unit on hand, it is time to start adding things to your aquarium water. This is where multiple tanks come in handy because the one that needs to be treated will need to be empty of fish and substrate. If you do not have a second tank at home, I suggest using as little as possible not to flood your main tank.

Most people use carbon when they buy it, which is fine, but you will want to run the RO unit for a day or so before adding any carbon to remove as much silicate from the water column as possible. This is the only time that the RO and carbon should ever be used together, in my opinion, because mixing them causes the negative ions found in RO water to be released.

To begin with, place your carbon inside of your filter and turn it on. If you only have one tank, you will need to take apart this filter, pour out the carbon, rinse it off thoroughly, and return it to its normal configuration. These steps should help you in learning how to remove silica from aquarium water.

Step Four: Periodic Maintenance

After you have begun using either your carbon or RO unit, monitoring the amount of silicate in the water is essential. You may need to use more than one brand of carbon if you buy several or run it for longer than three days, depending on how much silicate was in the aquarium water before you started treating it.

Periodic Maintenance

In addition to this, you will need to test the water every week for at least a month. It is important to do these things because some carbon brands only remove about 50% of the silicate from your aquarium water and need to be replaced often if they will work correctly.

The same goes for RO units as well. If you have a low-quality RO unit, then you will need to replace the filters often. If you change them too late, then it can cause algae growth in your aquarium, which may clog up your tank and require a complete cleaning.

Step Five: Rinse

After using either your carbon or RO unit, it is important to rinse them off as soon as possible. If you do not rinse them out, they will start releasing their ions back into the aquarium water and can cause a sudden increase in silicate concentration which may harm any fish inside.

Remove the carbon from your filter and rinse it off in a bucket of aquarium water. Do not use soap or detergents when rinsing your carbon because these chemicals can be harmful to the fish inside the tank and dirty up your filter.

Remove the Carbon From Your Filter

This is especially true for RO units, which should only be used with deionized distilled water that does not contain any calcium, magnesium, or sodium traces. If you do not use deionized water, then you will need to replace the filters halfway through your treatment process and clean out the unit once a month. This will help in how to remove silica from aquarium water.

Step Six: Preventing Accidental Death

Since you are adding chemicals to the aquarium water, preventing your fish from being exposed to them is best. Before adding carbon or RO units, reduce the amount of food you give your fish for a few days, not trying to eat anything while being treated.

It is also a good idea to keep them in the main tank because carbon and RO units do not remove ammonia from your aquarium water. If you place the fish in a separate tank, they will be exposed to even more ammonia because nothing filters that chemical from their environment.

If you have an extremely large number of fish that need to be treated, it may be good to place them in a clean bucket containing treated water while the carbon or RO unit is being used. Of course, your fish will not be happy, but it may help you avoid losing them after treatment is over if they are already accustomed to poor conditions.

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Step Seven: Add Carbon or Use RO Unit

Once your fish are separated from the water, and you have thoroughly rinsed off your carbon or RO unit, it is time to add them back in. Again, you should not notice any changes in the quality of the tank within the first few hours, so there is no need to rush this part.

Add Carbon or Use R

After 24 hours have passed, check for signs of algae growth in the aquarium. If there are no signs, then you can assume that your carbon is working correctly. However, if there are signs of algae growing in the tank, it means that the pollution level is too high, and you should consider replacing your carbon or running it longer before rinsing.

If you use an RO unit to remove silica from aquarium water, then go ahead and put it back in the tank after you have rinsed off the mineral cartridge. However, if you use the steps outlined above for how to remove silica from aquarium water, you can do it yourself.

Step Eight: Add More Plants

Since this process may be removing minerals from the water, it is a good idea to add more plants to absorb excess nutrients and prevent algae growth. You should also consider running carbon in your filter every other day if you want to help reduce any additional pollution levels.

When it comes down to it, removing silica from aquarium water can be difficult, and any process you use will take a lot of time and effort. If you truly want to remove all mineral traces, it is best to take good care of your fish and let natural processes go on uninterrupted.

Frequently Asked Questions

Is Silica Bad for Aquariums?

Silica is not bad for aquariums, but it is necessary for the natural cycle. Silica can be found in many freshwater and saltwater fish foods and plant fertilizers.

Many people wonder if silica is bad for aquariums because some of them have noticed a build-up on their substrate or driftwood, which they believe may be caused by silica. However, this buildup does not indicate that silica is causing harm to your tank; it’s just part of the natural cycle. Silica will dissolve into your water column and become part of the bio-filtration process, so you don’t need to worry about cleaning up after it has dissolved.

Is Silica Toxic to Fish?

No, silica is not toxic to fish. It can be harmful if it’s consumed in high amounts, but that doesn’t happen with the amount of silica present in fish food.

Silica can be found in different forms, like soluble and insoluble. Soluble silica is the form that occurs naturally in water and helps plants grow and absorb water. Insoluble silica, on the other hand, occurs when minerals are deposited onto rocks and sand beds as a result of weathering processes like erosion or tectonic movement. This type of silica is known to cause problems for humans because when we breathe it, our lungs may become clogged up with this mineral which causes lung cancer.

Use Silicone Caulk

Should I Reseal My Aquarium?

It is always better to seal your aquarium before adding any new fish. If the tank has a crack or leak, it should be repaired immediately. If there are cracks in the glass or leaks in the silicone gasket, it is important to fix them before adding any new fish and when doing so, use silicone caulk instead of epoxy resin.

After you have sealed your aquarium, wait for 24 hours before introducing any new fish and test the water chemistry levels with a pH test kit.

Can You Use Regular Silicone to Seal a Fish Tank?

No, regular silicone is not recommended for use with fish tanks. Silicone sealant is only meant to be used on silicone surfaces and will not adhere to a fish tank.

How Much Does It Cost to Reseal an Aquarium?

To reseal an aquarium, you need to find a reputable local glass repair shop. It will cost about $10-30 for the labor and about $40-50 for the new glass.

There Are Some Things That May Increase the Cost of This Project :

  • Using thicker glass than normal increases labor costs by 20%.
  • Using a large size of aquarium that requires more labor time and thus increases your costs even more.
Use a Large Size of Aquarium


The most common type of silicon in aquariums is orthosilicic acid, which can cause several health problems. In addition, silica buildup will also change the pH balance within an aquarium, which could lead to a dangerous situation for any fish that live inside it.

To avoid these dangers, you should remove all traces of silicone before long-term exposure occurs or if there has been significant accumulation over time. The conclusion paragraph is informative and provides information on how to remove silica from aquarium water.

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