Can You Keep Shrimps in Blackwater Tank?

Blackwater biotopes provide a natural and suspenseful ambiance at the aquarium. But considering the safety and health of the pet shrimps, it is a good option?

A Blackwater tank is an ideal place of habitation for shrimp. Tannin is a component infused in the water creating a blackwater environment, which helps to lower the pH level and promote shrimp breeding.

Blackwater provides the shrimps with a natural habitation ambiance. So, I am sure you are curious whether creating a blackwater tank would be suitable for your shrimps. In this article, you will find all details about shrimp and blackwater tanks.

What Is a Blackwater Tank?

Blackwater refers to the recreation of the Amazonian blackwater in the tank, which is acidic in nature and dark, brown in color. Even though the name has black in it, it is mostly brownish, almost like the color of herbal tea. What makes the color of water like that? Certain woods, decomposing plants, or components defuses acidic substances into the water which makes the water brownish.

Tannin is a polyphenolic organic acid that comes from oak tree wood or redwoods and dissolves in the water. Moreover, Humic and Fulvic Acids come from the decomposed wood and darkens the color into brown and black. With such organic acids, not only the color of the water but also the water parameter changes in the tank.

Tannin, Humic, and Fulvic are basically generic terms for many defusing acids coming from the decomposed wood. Since they are basically acids, the water parameter plummets into being acidic in nature. The pH levels of blackwater range from 5.0 to 6.5. Fishes who prefer slightly acidic water get benefits from such ambiance. Also, their contribution of creating carbon dioxide and adding nutrients overall creates the perfect ecosystem. Shrimps are also acid-loving creatures and blackwater can be an ideal environment for them.

Why Should You Keep Shrimps in Blackwater Tank?

In addition to giving the aquarium a dark and mysterious outlook, a blackwater tank creates a suitable habitat for the shrimps to stay in. There are numerous benefits of a blackwater tank which can be beneficial for the shrimps in general and in the time of breeding. Let us see why keeping the shrimps in the blackwater is a very good idea_

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Reduction of pH and Ammonia

The acids produced in the blackwater environment lower the pH level in the water but not by a significant number. Thus, the shrimp can get a cozy atmosphere due to the acidic water but won’t be startled by sudden parameter changes.  In addition to that, the ammonia level in the water is also reduced exponentially.

Below the pH of 7, ammonia (NH3) is converted to ammonium (NH4). Ammonium doesn’t have any negative effects on fish and water. We all know, how much chaos and disease ammonia can create for fish and shrimp. With slightly acidic water, the shrimps will thrive and be disease-free.

Keeps the Water soft

Humic acid works to lower the hardness of the water. When Humic acid is produced the carbonate hardness (KH) is brought down due to the lower acidic atmosphere. That helps to keep the water soft. Shrimps prefer to live in a soft water parameter. Since shrimps shed exoskeleton, their inner body remains vulnerable. And the excessive hardness of water can give a burning sensation to their skin.

Promotes breeding

In nature, shrimps receive a signal of breeding just before a rainy season or wet season, when the water level is lower. Because due to the heat, the dispersion of tannin is escalated and the blackwater becomes darker and browner to signal the shrimps to mate. By creating a similar ambiance in the tank, you can influence or promote the breeding of shrimps.

Reduces the growth of algae

A darker ambiance means that very little amount of sunlight can penetrate through the water. Thus, the algae growth can be subdued to a significant amount. Of course, it won’t be eliminated completely, and you won’t want that because shrimps love to munch on algae. But the growth rate will be reduced so your cleaning hand can get some rest.

Eliminates Fungus and Bacteria

Humic and Tannin defuse disease resistance acids. Blackwater has anti-fungal properties which can affect the eggs. Also, the skin of the shrimps can heal quicker because of the lower number of bacteria present in the blackwater. Due to the lower sunlight, the parasites can hardly grow and maximize in the water.

Which Shrimps can Live in the Blackwater?

All shrimps thrive in alkaline water where the pH is slightly on the acidic side. Tannin or Tannic acids create the water parameter suitable for all types of shrimps there are out there as pets. Red Cherry shrimp, Pinto shrimp, and bamboo shrimps are particularly fond of blackwater biotopes, even though being freshwater creatures.

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The Amazon has two families of freshwater shrimps. Palaemonidae has 14 species and Sergestidae has 2 to 3 species. Overall, 50 species originating out of the Amazon, can be very much compatible with the blackwater ambiance of the tank. Among them, Amazon tiger shrimp and Neocaridina davidi Shrimp are vastly available and suitable for blackwater biotopes.

Is There Any Negative Effect of Blackwater Tank?

Don’t rush into the shop to make the blackwater biotope after knowing about the benefits. Before you can commit to this, you must consider the probable cons of the blackwater biotope. This is not to discourage you, but to guide you and make you ready for that challenge.

Needs High Maintenance

Water management is to create a balance between the softness of water and pH level. This is not a task for beginners. In one way, you need to keep the water on the alkaline side, and in another way, you need to ensure the shrimps don’t get stressed and startled by a sudden change in the water parameters.

You need to maintain a tight schedule to keep the water in balance and check. The cleaning should be done twice a week at least. Also, a pH test and KH test must be performed each week to monitor the softness level and acidity range.

Risk of Acidosis

Blackwater biotope creates a slightly acidic ambiance in the water which is suitable and preferable to the shrimps. But this also imposes the risk of acidosis, which means the excessive presence of acid in the water. This may coarse the skin, skeleton, and mouth of the shrimp and penetrate into their organs. The high amount of acid will deter ammonia to convert into ammonium and the ammonia level is at risk of increasing as well.

Requires Knowledge of Water Parameters

Blackwater means creating an alkaline-based ambiance where all the other parameters of water shift with the pH level. If you are not careful or have comprehensive knowledge about the water parameters, water acidity, maintenance of shrimps, and their preference, this biotope might not be a good option for you.

What pH is Blackwater?

The accurate level of pH in the blackwater ambiance is extremely crucial. Because if the level is lowered too much, the corrosive nature of the acids will take upon the tank, and not only shrimps but also other fishes will not survive in those conditions. So, the pH level of the blackwater biotope should be from 5.0 to 6.5. It has been researched that shrimps thrive breeding in those pH levels best.

How Long Should the Blackwater Plants be Kept?

If you decide on creating a blackwater biotope for your shrimps, you must be aware of the basic information about the maintenance. Because you can’t really implant the botanicals into the tank and forget about it. If you leave the plants or wood longer than it is necessary, the water will be too acidic for the shrimps to survive.

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Generally, the plants need to be input for 1-2 weeks, depending on the size of the tank, the type of the plant, and the number of shrimps on the water. After removing the plant from the tank, the water will sustain the acidic parameters for 1-2 months. If you observe the discoloration of the water, you need to do a patch test of water and implant the plant again for more dispersal of tannin.

Can Blackwater Ambiance be Reversed?

If you do not prefer the blackwater biotope in your tank or the shrimps can’t adjust to the ambiance, you can reverse the position without a hassle. But don’t change the water frequently because it won’t be healthy for the shrimps. You have some options before you.

Add Seachem

This cleanser helps to remove the organic waste inside the tank. Since tannins are basically organic acids, they can absorb the substance can and clear the water. It can clean the excessive amount of ammonia, and nitrate from the water.

Add Activated Carbon

Activated carbon in the filter will help to neutralize the water and convert the alkaline water into plain water. This process will take some time and trap the tannin instead of eliminating it.

Perform Water Change

Gradual water changing can be another option for reversing the blackwater ambiance. Ensure to remove 20% water each week so that shrimps can be adjusted with the settings.

Water changing with a cleanser or filter will yield the best result to reverse the biotope. If the shrimps show some negative impact on this environment, quickly change the alkalic biotope.

Final Words

Blackwater biotope creates a natural, Amazonian ambiance inside the tank, and shrimps not only love to live but thrive in such an environment. It promotes breeding and reduces fungus and bacteria in the water. If you can commit to maintaining such ambiance, you can definitely keep the shrimps in the blackwater tank. 

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Muntaseer Rahman

About Author

Hello, I’m Muntaseer Rahman, the owner of I’m passionate about aquarium pets like shrimps, snails, crabs, and crayfish. I’ve created this website to share my expertise and help you provide better care for these amazing pets.


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