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How Do Eco-Bio Blocks Improve Aquarium Water Quality?

James is a longtime aquarium keeper who enjoys sharing his product experiences with others.

Eco-Bio Blocks aren't cheap, but they can save you a bundle in time and effort.

Eco-Bio Blocks aren't cheap, but they can save you a bundle in time and effort.

What Exactly Is the Eco-Bio Block?

Achieving near-perfect water parameters is essential to maintaining a healthy-looking ecosystem in your aquarium. Eco-Bio Blocks are bacteria-treated stones comprised of volcanic rock and cement that you can place in your aquarium tank. They are designed to minimize the frequency of water changes necessary to maintain a good chemistry in your aquarium by reducing harmful ammonia, nitrites, and nitrates.

While monitoring the levels in your tank and changing the water is still necessary, these Blocks are supposed to make your life easier by reducing the frequency of these chores. I've tried the Blocks in my saltwater tank, but they can be used in freshwater tanks as well.

Eco-Bio Block Quick Facts

  • Composition: Volcanic rock and cement mix
  • Active Component: Bacteria
  • Used to Mitigate: Ammonia, nitrites, and nitrates
  • Lasts: Approximately two years

What Is the Bio Block Made of?

Before examining how it clarifies cloudy water conditions and improves overall chemistry parameters in your tank setup, let's take a look at what exactly the Eco-Bio Block is. Compositionally, the Eco-Bio Block is a unique conglomeration of porous volcanic rock and cement ingredients imbued with water-clarifying bacteria. When submerged in water, the bacteria hosted by the Block begin to reproduce.

How Does the Eco-Bio Block Work?

The Bio Block naturally improves water clarity and quality in both freshwater and saltwater systems. When the Bio Block comes in contact with water, the bacteria within the Block begin to multiply within about half an hour. Talk about rapid cycling!

The bacteria released by the Block oxidize surrounding ammonia, nitrites, and nitrates. In turn, water quality and clarity are both improved. Let me mention that the Bio Block lasts for up to two years before the Block begins to lose its beneficial bacterial effects.

I've introduced several Eco-Bio Blocks to my tank in addition to performing regular maintenance and frequent water changes to ensure my water's quality is as high as possible.

I've introduced several Eco-Bio Blocks to my tank in addition to performing regular maintenance and frequent water changes to ensure my water's quality is as high as possible.

My Review of the Eco-Bio Block

I can personally attest to the fact that—at least in my case—this Block does work. As you can see in my photo below, the 20-gallon saltwater tank that I started cycling this year has obvious water clarity and quality (not as obvious are the low nitrate levels). In the center of the aquarium is a large Eco-Bio block.

In about a week's time, the Bio Block made a substantial difference. Remember, this is without adding live cured rock, which is often used as a natural biological filter to start the cycling process in new aquariums like this one. So basically, what two medium pieces of live rock (which would cost about $40) would have accomplished, one large Eco-Bio Block (which cost me about $29) achieved in less than half the time. And my nitrate level at this point in time is barely 5 ppm.

Nitrates are not necessarily a huge problem for many fish species, as long as they do not exceed 39 or 40 ppm maximum. But if you want to start an all-coral tank, as I plan to do eventually, you definitely want all water chemistry parameters to be as near to perfect as possible. And that includes a nitrate reading of nearly zero.

If It Works for Me, It Might Work for You

As explained in the previous paragraphs, I can comfortably say that, to date, the Block has assisted in speeding up the cycling process in my tank, in addition to helping the water stay healthy-looking. The mechanism through which the unique bacteria released by the Block clarify tank water needs to be researched further by other experienced aquarists. For now, all I can say is it works for me!

I placed two Eco-Bio Blocks in my aquarium approximately two weeks prior to taking this photo.

I placed two Eco-Bio Blocks in my aquarium approximately two weeks prior to taking this photo.

How Does the Nitrogen Cycle Work?

Familiarity with basic water chemistry and the nitrogen cycle will help you understand how this Block fits into an aquarium environment. It does a better job aiding in the cycle than an aquarium filter, plants, or even live rock, though those components are still necessary for achieving high-quality water chemistry, which equates to clear water.

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The Nitrogen Cycle in Your Aquarium

The cycle begins with decomposing matter. Your fish's fecal matter, decaying plants, or even a few flakes of fish food that begin to rot can all activate the nitrogen cycle because they release ammonia, which is very toxic to most aquarium inhabitants. Naturally occurring bacteria in the water will then turn the ammonia into another toxic compound called nitrite. Finally, a different type of naturally occurring bacteria in the water will convert the nitrite into less harmful nitrate.

Although less harmful than ammonia or nitrites, nitrates can and do stress out our fish friends and some sensitive invertebrates like corals. Frequent water changes are helpful in removing these nitrates.

Larger aquariums require less maintenance as a general rule. Aquarium plants can help remove nitrates in freshwater tanks, and live rock can do the same in saltwater aquariums. This is exactly what the Eco-Bio Block does, but the Block does it faster. It continually increases the "good" bacteria in your aquarium water.

The video above explains this process in greater detail. It is important to remember that you need a good plan to maintain water chemistry through water changes and components such as plants, live rock, and the Bio Block. I cannot stress this point enough. Without good water chemistry, you won't have a healthy tank capable of supporting any type of marine life or clear water conditions.

The Bio Block may help you achieve optimal chemistry sooner than regular maintenance alone, but you will still need to do weekly or bi-weekly water changes. Just try to remember these three "P"s: planning, patience, and persistence (in that order)!

Before the Eco-Bio Block

After Two Weeks With the Eco-Bio Block

In the videos above, you can clearly see a substantial improvement in this individual's freshwater tank water within two weeks.

YouTube videos are YouTube videos, and one result does not a conclusive study make. To know for sure whether the stone will work in your tank, you'll have to try it yourself.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

Questions & Answers

Question: Did your rock have any residue on it?

Answer: Over a period of time, my blocks may have accumulated a little residue but nothing to be overly concerned about. You can take an old toothbrush and clean it vigorously to remove any residue if you wish. I usually use white vinegar undiluted to clean inside my aquarium. It won't hurt aquatic life. Also after about a year, it's a good idea to replace your boo rocks with new ones. Hope this helps answer your question.

Question: Can you put the rock in a canister filter?

Answer: Yes, you could put the rock in a larger canister filter like the Sun Sun for example. And only the smaller eco rock, since there are generally 2 sizes, a small rock and one a bit larger. However I usually place my eco rocks embedded in gravel at the bottom of my aquarium. But once again I see no reason why the small eco stone placed in one of the canister filters media trays wouldn't work also.

Question: How often should I replace eco-blocks in my aquarium?

Answer: Every 6 months for the best results, but at least once per year.


James Bowden (author) from Long Island, New York on October 30, 2020:

Hi Diana;

Even though I never did this, I've always had a 16 to 20 gallon tank. In a 1 gallon tank which is called a Nano tank, the small size stone would not cause any harm. But to be on the safe side, try breaking the small stone in half. Use 1/2 a small stone rather than the whole piece. Hope this helps answer your question.


Denise on September 08, 2020:

Is it okay to use this stone in a small (1 gallon) betta fish bowl?

James Bowden (author) from Long Island, New York on March 10, 2016:


Appreciate you stopping by and reviewing my article on the Bio Blocks. Actually the Eco-Bio Blocks are relatively new to the market and are excellent for improving water conditions in both salt and freshwater aquarium set ups.

And when I was a kid I strictly raised fresh water species. But as I got older I found maintaining a saltwater reef aquarium not only challenging. But actually a lot more rewarding, as well as equally satisfying.

It's great for the mind and much like writing - a form of relaxation or meditation. Besides it can keep your mind off of less positive things. Remember you're never too old to get back into this hobby.

Whether it be starting up that freshwater tank when you were a kid again. Or as I recently have done. Graduated to bigger and better things with a saltwater marine reef aquarium. Again glad you found the article informative.


Glenn Stok from Long Island, NY on March 09, 2016:

This is a very interesting explanation of Eco-Bio Blocks. Back in the days when I used to breed fish as a hobby (when I was a kid), I never knew of this. Maybe they didn't exist at that time. I remember how difficult it was to keep the tanks clean and the water a healthy environment for the fish and plants. The Eco-Bio Blocks definitely do help with this by controlling the Nitrogen Cycle.

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