How to Reduce Water Hardness in Aquarium?

Water hardness is also called general hardness, and it’s the measure of the salts dissolved in the water. This focuses mainly on magnesium and calcium. If there’s a low GH, it’s soft water, but if there’s a high GH number, it’s hard.

Typically, this means that soft water doesn’t have much magnesium or calcium and hard water has more. It focuses on your water source, so tap water rarely has a problem. Still, it’s possible to have hard water and want to reduce that for your fish’s safety.

We’re going to discuss ways to reduce water hardness. That way, you can figure out the right method for you.

Why Is Water Hardness Important For the Aquarium?

You should be monitoring the water hardness in your aquarium because of osmoregulation. This is a natural process, and the fish do it automatically. It just happens and is similar to human breathing.

In a sense, osmoregulation is the process when the fish balance the water and salts in their body with what’s outside the body. If there is an imbalance, it stresses the fish and could cause death.

Electrolytes are another important factor for water hardness. These are the minerals and salts used to conduct electricity when they’re dissolved in water. Such electrolytes are important for gill development, digestion, bone growth, and more.

Fish have to get electrolytes from the water to be healthy. If there’s no water hardness at all, they can’t do that. However, when there’s too much, they could get sick.

Appropriate Water Hardness Levels for Aquariums

The right water hardness level depends on what’s in the tank. Typically, if you have tropical fish, you should keep the water hardness between four to 12 dGH (degrees of general hardness).

This is the same for a pond and is quite similar for a shrimp tank. However, if you have African cichlids, you want it to be between 12 and 20 dGH.

How to Test the Water Hardness

Water hardness is invisible. This means you can’t look at it to tell if it’s soft or hard.

You can use an aquarium test kit that’s designed for KH and GH. They’re quite easy to use and can perform hundreds of tests.

Ultimately, you shouldn’t have to test your water hardness level all the time. However, if you know you have soft/hard water, it’s often best to do that. Most people test it when they do a water change.

What Happens When the Water Hardness Is High?

There must be some water hardness in the aquarium so that the fish get the nutrients they need. However, a high water hardness level can cause many problems:

New Fish Might Die

There is some debate about this, but hard water could be too much for your fish to handle. If they’re acclimated to the hard water, this isn’t likely to happen. Still, you don’t want to risk dead fish that you paid for and can no longer enjoy.

What happens if you purchase a new fish, and the aquarium has a high water hardness level than the pet store? Typically, you put them into osmotic shock. Though this can take a few days to see, it’s going to kill them.

However, most people don’t realize that osmotic shock isn’t instantaneous. Therefore, you may think the fish is unhealthy and already dying.

Acclimation is key, and you can do it by dripping water from the tank into the fish’s container. By adding the hard water a bit at a time, fish can adapt to it.

Breeding

If you plan to breed new fish, they aren’t going to breed if the water is very hard. Typically, the fish breed during the rainy season, and when there’s extra water, the hardness level drops. That dip tells them to start breeding.

Live Plants

You may have sensitive plants that you want to keep in the aquarium. They may not grow well or at all in hard water. You can either choose plants that grow in your hard water level or reduce it.

Methods to Lower Water Hardness Levels in an Aquarium

Though it’s easier to increase water hardness in your aquarium, it is possible to lower it. However, if you have issues keeping it at the right level, it might be best to have hard water fish. Let’s take a look at the different ways you can reduce water hardness levels:

1. Deionized Water and Reverse Osmosis

If you notice that you have to lower the water hardness level each time you do a water change, consider an RO/DI system. This device can remove minerals, salts, and other contaminants. That way, you have almost pure water.

The water is going to be very soft. In fact, there is no water hardness at all. However, every fish needs some hard water, so you’ve got to counteract it.

To do that, you can dilute the tap water with some RO/DI water to get the right hardness level. You may also use the RO/DI system with a re-mineralizer. That can raise the water hardness level to the right amount.

2. Distilled Water

Distilled water has been turned to steam, which is then collected. The steamed water leaves behind the minerals and salts, so you get pure water.

Like the RO/DI system, distilled water has no water hardness level at all. You have to supplement it with something. This includes mixing it with tap water or re-mineralizing the water.

3. Peat Moss

Peat moss can be added to the aquarium to soften the water. Put it in a mesh bag and place it inside the filter. When water passes through your peat, it traps calcium and magnesium.

You’ve got to remove the peat periodically and replace it with fresh options. However, you’re effectively removing the minerals to soften the water.

The issue is that it’s not precise for lowering water hardness. If it’s extremely high, peat might not make a difference at all. It also includes tannins, which could reduce pH levels, too.

Conclusion

If you know that you have hard water, it is essential to lower it. The water hardness level can hurt your fish or kill them, especially if you’re a breeder or don’t acclimate new fish to the tank. However, it’s not as easy as you might think to reduce water hardness.

There isn’t a magic liquid you can use, and it’s going to take some trial and error. Therefore, you want to have some water hardness test strips on hand to help you monitor water hardness levels.

From there, you can find the right solution for lowering water hardness in the tank. This might include using peat moss, adding tap water to distilled water, or something else. We’ve talked about the various options available to you.

Now is the time to figure out if you want to reduce water hardness in the aquarium. Those who already have fish may be required to do this. If you’re just starting out, it might be best to choose fish that can handle that water hardness level.

Regardless of what you decide, you now understand more about water hardness (GH) and why it’s necessary. Consider your options and lower water hardness so that your fish thrive. That way, you can enjoy them for many years to come.