How Aquarium Water Hardness Is Affecting Your Fish

How Aquarium Water Hardness Is Affecting Your Fish

If you have been keeping fish for any length of time, you have likely heard about water hardness and how it can affect your fish.

Water hardness can have several impacts on fish, both positive and negative.

In general, hard water is better for fish than soft water.

It helps to stabilize the pH of the water and to provide essential minerals that fish need to survive.

However, too much hardness can be harmful to fish.

It can cause the water to become too alkaline and can lead to health problems like skin lesions and breathing difficulties.

In this article, we will take a closer look at how water hardness affects fish and what you can do to ensure that your aquarium’s water hardness is just right for your fish.

What Is Meant by Water Hardness?

Water hardness is a measure of the dissolved minerals in the water.

It is expressed in terms of either degree of hardness (dGH) or parts per million (ppm).

Water can be soft, medium-hard, or hard. Soft water contains few dissolved minerals, while hard water contains many.

The most common minerals found in hard water are calcium and magnesium.

These minerals can come from natural sources, like rocks and soil, or from man-made sources, like fertilizers and septic systems.

Although these minerals are not harmful to fish in small amounts, they can cause problems if the water becomes too hard.

Why Is Hard Water Problematic?

When the water hardness becomes too high, it can cause a number of problems for fish.

High levels of dissolved minerals can make the water too alkaline (pH above 7.0), which can be harmful to fish.

It can also make it difficult for fish to absorb essential nutrients from their food.

This can cause the fish to become malnourished and can lead to health problems like skin lesions and breathing difficulties.

In addition, high levels of dissolved minerals can cause the water to become cloudy and can reduce the oxygen levels in the water.

This can be harmful to fish, especially if they are already stressed from being in a tank.

Some of The Problems Water Hardness Can Cause Are:

  • The fish cannot absorb essential nutrients from their food. This can lead to health problems like skin lesions and breathing difficulties.
  • Major health problems like stunting and fin rot.
  • It can impact the fish’s lives and cause death.
  • You may observe that the fish do not reach their potential size or health.

Why It Is Important to Monitor Water Hardness Levels?

1. You Have Either Very Soft Or Very Hard Water

Keeping particular sorts of paradise fish that prefer to reside in the center of this range might be tough if your water source is soft or hard.

You’ll need to keep an eye on your GH and adjust it as needed.

2. You Want to Keep A Specific Type of Fish

Some fish such as cichlids prefer hard water, while others like discus prefer soft water.

If you want to keep soft water fish, you must maintain a close eye on the GH water quality.

How to Lower Aquarium GH – Decrease Hardness

Softening hard aquarium water is a simple process that can be done in a number of ways.

1. Peat Moss

Peat moss is one of the most popular and easy-to-use choices available.

However, you can’t be sure about the accuracy of this technique.

If you’re raising fish that are sensitive to water hardness, it’s possible that this approach won’t produce the outcomes you want.

Also, keep in mind that peat moss doesn’t work instantly.

Instead, it may take some time to decrease the number of minerals from the water.

2. Water Softening Pillows

Water softening pillows are excellent for removing extra minerals from aquarium water.

You may put these cushions in the tank and remove them after a while.

During this time, the pillow will capture all of the potentially harmful minerals from the water and make it soft.

Water softener pillows have a high upfront cost. They are costly, to say the least.

You may require hundreds or thousands of pillows each year, depending on your water change schedule.

The best water softener pillow on the market is  API’s Aquarium Canister Filter Filtration Pouch.

This filter removes contaminants including heavy metals and hard minerals from tap water.

3. Reverse Osmosis

Reverse osmosis is the most laboratory-based approach to soften aquarium water without changing your fish and plants’ lifestyles.

The choices for the best RO technology for an aquarium are numerous.

Depending on the size and type of the tank, you can pick from one of the finest RO systems for aquariums.

Reverse Osmosis will also clean the source water of pollutants, in addition to lowering your costs.

The world’s largest industries, if you didn’t already know, utilize Reverse Osmosis to soften water at their facilities.

You should also keep in mind that you’ll need to mix RO water with tap water if you want the desired softness and hardness balance.

4. Driftwood

Driftwood isn’t as successful as the aforementioned treatments, but it’s still an excellent solution.

It breaks down tannins and generally transforms the tank water color to brown, but it does not harm the fish.

It’s a good idea to pick up driftwood from your local fish store.

5. Rainwater Harvesting

What if you don’t have access to a water supply that includes minerals?

If you live in a location that receives appreciable amounts of rain, such as Southern California, then the greatest solution for obtaining soft water for your aquarium is rainwater harvesting.

Rainwater, of course, does not contain the minerals that cause hard water issues.

So, if you can collect this pure water during the rainy season, you may use it in your aquarium.

You may add as many of these systems as you like to get soft water for household usage, but you’ll need a massive tank, among other things.

How to Increase Aquarium GH – Raise Hardness

If you live in a location that has soft water, it’s possible to harden it using various methods:

1. Using Tap Water

You might not be aware that if your tap water is moderately hard or very close to extreme hardness, all you have to do is turn on the faucet in your kitchen sink.

Using tap water may be all you need to get back the overall hardness lost by fish and plants in your aquarium.

This technique does not require any special procedures or chemicals.

However, if your tap water is soft or if you wish hard water to be harder than your tap water, this process may not provide the desired results.

2. Crushed Coral

A crushed coral substrate can increase the hardness of your aquarium water.

This is an old-fashioned technique that many aquarists still use today.

It’s a great option if you have fish that prefer harder water or if your tap water is too soft.

It has a high concentration of calcium carbonate and causes the pH in the aquarium that it is living in to rise.

You may either place crushed coral in a media bag or combine it with pebbles.

When you add crushed coral to your water, the general and carbonate hardness levels will both rise.

Note: Crushed coral has an extremely high pH, which may be harmful to fish that like soft water with low acidity levels.

3.  Aragonite

Aragonite is another substrate option that can help to harden your aquarium’s water.

It is a form of calcium carbonate, just like crushed coral, and it also raises the pH in your tank.

When you use aragonite in your aquarium, the general hardness and carbonate hardness levels will both rise.

Just like crushed coral, aragonite also has a high pH that can be harmful to fish that prefer soft water with low acidity levels.

4. Remineralized Water

Remineralized water is water that has been treated with chemicals in order to restore the minerals that were lost when the water was processed.

To use it, simply mix distilled water with a calcium-based or magnesium-based remineralizing agent.

This will add back the minerals that were removed when you distilled the water.

When you use this technique, the general hardness and carbonate hardness levels of your aquarium will both rise.

This is a great option if you want to soften your water without using any crushed coral or aragonite.

5. Limestone

Limestone is a type of sedimentary rock that is composed mostly of the mineral calcite.

It forms in oceans and other bodies of water where calcium carbonate is deposited by organisms such as corals, shells, and plankton. Over time, these deposits can build up to form limestone rocks.

Adding limestone to your aquarium can help to harden the water. The calcite in the limestone will dissolve and release calcium and carbonate ions into the water.

These ions will help to raise the pH and hardness of the water, making it less hospitable to algae and other pests.

Does Aquarium Salt Increase Hardness?

Some aquarists add aquarium salt to their tanks in order to increase the hardness of the water.

However, this is not necessary and can be harmful to some fish.

Aquarium salt does not contain any of the minerals that are necessary to harden your water.

Instead, it contains sodium and chloride ions, which can raise the pH and make the water more alkaline.

This may be harmful to fish that prefer soft water with low acidity levels.

What Is the Best GH for Your Aquarium?

The optimum GH levels are solely determined by what you have in your aquarium.

Let’s look at some recommended ranges for various aquarium types.

While the measurements can be recorded as parts per million (PPM), we like to use degrees of overall hardness (dGH).

One dGH is equivalent to about 17.9 PPM.

The following are only suggestions. The specific requirements of your fish, plants, and invertebrates may differ from these ranges.

  • Tropical Fish Tank: 4-12 dGH
  • Shrimp Tank: 4-8 dGH
  • African Cichlid Tank: 12-20 dGH
  • Discus Tank: 3-8 dGH
  • Planted Tank: 3-8 dGH
  • Brackish Tank: 12-20 dGH
  • Axolotl Tank: 7-14 dGH
  • Pond: 4-12 dGH

What Fish Do Well in Hard Water?

There are many fish that do well in hard water. Some of the most popular ones include:

  • African Rift Lake Cichlids
  • Brackish Water Fish Paradise FishMost
  • Central American Cichlids
  • Livebearers – Guppies, mollies, platies

How Do You Test the GH of Your Aquarium?

The most crucial thing to know is that your aquarium’s GH isn’t visible.

You won’t be able to tell the difference between soft water (low GH) and hard water (high GH) just by looking at it.

To figure out the GH of your water, you must test it.

And to do this, you can either use a test kit or test strips.

Using Test Kits

To use a test kit, you must first fill a test tube with some of your aquarium water.

Then you add a few drops of the GH testing solution to the water and shake it up.

After a few minutes, the reaction will settle and you can compare the color of the water to the color chart that comes with the kit.

The API Test Kit is one of the most popular test kits on the market.

It tests for a variety of water parameters, including pH, ammonia, and GH and you can find it at most pet stores.

Using Test Strips

Test strips work in a similar way to test kits.

You simply dip the strip into your aquarium water and wait for a few minutes.

Then you compare the color of the strip to the color chart that comes with the package.

Test strips are much less accurate than liquid test kits.

However, they are much easier to use and can be used to test a variety of water parameters, including pH, ammonia, and GH.

You can buy test strips at most pet stores and online.

How Often Should I Test The GH of My Aquarium?

Unless you have exceptionally hard or extremely soft water or wish to keep a delicate species of fish, most aquariums do not require testing for GH on a regular basis.

However, if you must, we recommend checking it once every time you do your aquarium maintenance, such as a water change.

Last Words

The GH of your aquarium can have a significant impact on the health and wellbeing of your fish.

So, it’s important to be aware of the GH levels in your aquarium and what that means for the types of fish you can keep.

We hope this article has helped you better understand aquarium water hardness and how to keep your fish happy and healthy.

If you still have any questions, please share them with us in the comment section below