Removing silicates from aquarium

Removing silicates from aquarium?

Silicates have a bad reputation for ruining the natural beauty of aquariums. Obviously, building an enchanting look and healthy ecosystem in an aquarium takes a lot of effort. So, removing silicates from aquariums is essential to maintain the water quality, prevent algae growth, and create an environment where your aquarium mates can thrive.

There are various easy methods to remove silicates from aquariums. First of all, cutting the source where silicates are coming from is the best way to control their overgrowth. Furthermore, the installation of RODI units or protein skimmers, the use of removing compounds, and the addition of a robust filtration system are the best ways to remove silicates.

Do you know silicates are not as messy and threatening for your aquarium inhabitants as their impact on diatoms? So, consider proactive methods to remove silicates from aquariums before they seize control of everything in the tank. I am going to recommend the following works-for-all-cases methods to keep your tank silicates free.

Let’s scroll down to opt for one of the perfect treatments to keep a happy aquarium.

What is silicate in aquariums, and where does it come from?

Silicate in aquariums refers to dissolved silicon dioxide (SiO2) compounds that are present in the water. There is no doubt it’s one of the most abundantly found minerals on Earth. It is found in glass, quartz, sand, rocks, soils, granite, and sandstone.

You know silicate itself is not harmful to fish or aquatic life in low concentrations. However, high concentration of dissolved silicon dioxide is sometimes problematic. The growth of single-celled algae is one of the most concerning issues that arise first due to high silicate levels.

Is silica good or bad for aquariums?

Silica is both good and had for aquariums. I mean, it depends on the context. We can’t label it as completely bad or completely good for aquariums. It’s a natural substance, and most of the marine life depends on it for their growth and health.

On the other side, many reef aquarists have called it a problematic substance if not balanced or monitored correctly. The insighty dust-like appearance of tanks is prevailing due to excessive silicate content. So, silicate is not that bad or not even that good.

How do we test for silicates in aquariums?

There are various ways to test for silicates in aquariums. Here are a few of them:

  • If your water seems rusty or brown, it’s a clear indication that it has a high level of silicates in it.
  • If you run your fingers slightly on the walls of the fish tank, they’ll turn brown, or you’ll start feeling gritty.
  • You can use a silicate test kit and follow the instructions written on the instructions menu. This is another effective way to test silicates in water.
  • Silicate test strips are an alternative to liquid test kits. They offer a quick and convenient way to estimate silicate levels.

You can also consult with a local aquarium expert or store that offers water testing services with the help of specialized equipment.

How to remove silicates from aquariums?

silicates from aquarium

Let’s delve deeper into a few of the best methods to remove silicates from aquariums:

  1. Cut off the source of silicates:

There could be many sources from where silicates get their way into your fish tank. Luckily, I have found the right solutions for each of these sources.

  • Tap water:

Tap water is a natural source of excessive silicate content. For example, some waters, like those coming from rivers, have large quantities of dissolved silicates that affect your aquarium’s health.

Moreover, water processors often introduce silicates to prevent copper and lead seepage from pipelines. It also serves to raise pH levels. So, make sure your natural water source has low levels of silicates.

  • Substrate:

The substrates you use in your aquariums have a rock called quartz. However, the quartz is not pure. It contains more than 2% silica.

Also, the commercial sand and silica combine to quickly dissolve a few undesirable substances in your aquarium’s water. So, always choose a suitable substrate for your tank and have some caution. Otherwise, things will get worse if the substrate settles down!

  • Salt:

Salt mixtures are another significant source of silicate supply in your aquarium. Specifically, if you use table salt, it can cause more and more silicates and iodine leakages.

You know, the salt mixture we buy that states “it’s silicates-free” has a small quantity of silicates. Therefore, you must select a high-quality salt mixture to avoid the addition of silicates in the aquarium.

  1. Install RODI units:

The products of RODI manufacturers for fish tanks are masters of removing silicates from aquariums. Many hobbyists reviewed RODI products as one of the best devices to extract large amounts of silicates from their aquariums. SpectraPure MaxCap RO/DI system is the perfect solution to incorporate a high silicate removal.

It helps to remove 90% of impurities from your aquarium’s water. You can test your filtered water and check if silicates are still left or not. Some aquarists like to purchase pre-made RO water, which is also an excellent approach to get silicates-free aquariums.

  1. Silicate-removing compounds:

Using silicate-removing compounds is one of the most cost-effective and straightforward methods to get rid of silicates and diatoms. Try to place them in a corner of your aquarium where there is enough water circulation, such as:

  • In the filter
  • Sump
  • Spots with more water contact

The time span of these substances is very short. So, replace these silicate-removing compounds more often, especially when you start seeing signs of brown algae.

  1. Installation of protein skimmer:

A protein skimmer is a mechanical filter that uses a filtration system to remove unnecessary organic molecules of water. Its specialty is to remove the organic molecules right before they start producing ammonia. It helps to remove the following unwanted things:

  • Toxins
  • Unconsumed food
  • Waste material
  • Silicates

Thus, it overall enhances your aquarium’s water quality. Also, it raises the levels of dissolved oxygen to reduce silicates.

  1. Introduce algae grazers and optimize lighting:

Algae eaters like snails, specific fish species, and shrimp are best to prevent algae growth (often caused by silicate). Interestingly, if you adjust the duration and intensity of lighting, it will limit the intensity of silicates in the tank.

What are the recommended silicate levels for aquariums?

The recommended silicate levels for aquariums vary. It depends on the type of aquarium and the specific needs of the organism you’re keeping. However, in general:

  1. Freshwater aquariums:

You should keep the silicate levels as low as possible, typically below 1 mg/L (parts per million). Moreover, some freshwater plants and fish are more sensitive to silicates. So, maintaining low silicate levels is essential.

  1. Marine (Saltwater) aquariums:

Silicate levels in marine aquariums are maintainable at deficient levels, ideally below 0.1 mg/L. As you can see, the overgrowth of unsightly diatoms and other issues in marine water are all due to high silicate levels.

Important note: The suitable silicate level for every aquarium inhabitant, like different species of fish, plants, and invertebrates, is different. So, the best practice is to research the specific requirements of your aquatic life.

How to prevent the growth of silicates in aquarium water?

Even though you have removed all the unwanted silicates and substances from your aquarium, they can haunt you anytime. Hence, here I’m sharing a few tips to prevent the comeback of silicates in your tank:

  1. Install a filtration system:

If you install a robust filtration system, it will start removing silicates from the aquarium. Also, filtration systems require proper cleaning and checking to get the most out of them. However, if your filtration system is poor, more silicates will be in your fish tank.

  1. Don’t overfeed tank inhabitants:

If you feed enough food to your fish, it will quickly gobble up all the food, and the aquarium will remain clean. On the flip side, more food waste means overgrowth of silicates and brown algae. The best practice is to divide your fish meals into small portions and feed them when necessary.

  1. Check food content:

Some of the foods you feed your fish contain a quantity of silicates. Ensure you check the food content and make sure they do not have any silicates. Otherwise, you’ll harm your tank unintentionally.

  1. Mind your decor:

Aquarists often do everything to remove silicates from their aquariums, but they do not stop overgrowing. Why does it happen? It is because they don’t pay heed to their decor.

The decorations often contain materials that spread silicates in water. So, have some caution with decorations and rocks that can leach silicates.

  1. Change water frequently:

If you want to minimize silicate expansion, regularly change your aquarium water. It will give a clean ecosystem to your fish.

Frequently Asked Questions:

  1. Does phosguard remove silicates?

Yes, phosguard is one of the best silicates remover. More importantly, it’s a safe product for marine use. Here’s a worth-watching YouTube video about Seachem PhosBond.

  1. Does RowaPhos remove silicates?

Yes, RowaPhos helps to remove silicates effectively. Actually, it’s a unique ferric hydroxide molecule. It was invented for efficient silicate removal in both saltwater and freshwater environments.

  1. Can carbon remove silicates?

No, carbon cannot remove silicates.


So, we come to the end of “removing silicates from the aquarium.” We found silicates are not a big deal if you are determined to remove them to keep your aquarium’s water neat and healthy. All you need to do is to follow some easy steps. It doesn’t matter which method is most useful or convenient; try to choose the one that will not harm your fish and other living organisms.

After all, it’s all about your fish health. So, do you find this article helpful? Which method do you think is the right one for your aquarium? Let me know your views in the comments section.

Thank you for reading!