One of the things aquarists have had to deal with fish keeping is kh. However, it can be difficult for newbies to tell what it is and how different it is from gh and other water conditions.
You should know that Kh plays a role in your fish tank aquarium, and too low of it can be problematic. As much as gh, alkalinity, nitrate, and other chemical components are important, so is carbonate hardness (kh).
This is why you need to know its implications and how to raise kh in aquariums. What do you need to know, and how can you raise kh?
It’s simple; you just need the right guide and tips. Let’s get into it.
Why is kh Important in An Aquarium
Carbonate hardness (kh) is one of the ways to check and judge water quality in aquariums, and it measures dissolved carbonate concentration and bicarbonates in fish tanks. The ideal kh helps to keep the water in the tank at stable parameters, and when it’s low, it can result in spikes of some other compounds in the aquarium, like gh.
You may not know it, but your tank’s kh level needs to be at the optimum for your aquarium to be healthy and habitable for your fish. What is the ideal kh level anyway?
Ideal kh levels
The appropriate kh level differs for different tanks depending on the kind of fish you keep. And sometimes, kh can fluctuate in tanks due to some situations that will be discussed later.
As a general rule, the ideal kh level for a freshwater aquarium is between 4 to 8 dKH, irrespective of the fish species you keep. However, some species prefer the carbonate hardness to be more than that and, ultimately, a high water hardness.
The ideal kh levels for the different freshwater aquariums are:
- 4 to 8 dKH for tropical fish tank
- 1 to 2 dKH for discus fish tank
- 5 to 9 dKH for cold water fish tank
- 10 to 12 dKH for African cichlid tank
- 6 to 12 dKH for a heavily planted tank
- 2 to 4 dKH for a cherry shrimp tank
You should research the fish you intend to keep for their ideal kh so you can raise your aquarium’s water quality to that level. You should also ensure that while you’re raising the kh to the ideal level, you don’t over raise the water hardness and dampen the water quality.
Side effects of low kh
You won’t need to raise kh if there are no consequences. But a very low kh can affect all the aquatic life living in your aquarium.
So, what happens when the kh is low?
- It results in pH deterioration and causes it to fluctuate rapidly.
- It can cause fish shock and death due to the sudden pH changes.
- When the water becomes too acidic from raised pH, it can affect live plants in the aquarium.
Benefits of Raising kh in Aquariums
A low kh is very dangerous to the aquatic life present in your aquarium. When the carbonate hardness becomes lower than 4.5 dKH or the ideal one based on the fish you keep, you need to do something about it unless it’s a breeding tank for soft water fish.
Raising the kh in your fish tank will do your fish a lot of good. It will help them stay healthy and allow you to maintain optimum water quality.
How does that work?
1. High kh helps prevent pH crash
Low alkalinity in fish tanks equals a rise in acidic components in the aquarium, like nitrites and nitrates. This can make pH crash which is terrible for your fish.
Therefore, raising kh in tanks affects the pH and somehow brings it back to its ideal level. But of course, you would need to check the pH level at intervals as you raise the kh.
2. Prevent pH fluctuations
If your kh fluctuates, it affects pH stability as well. Having a balanced kh ultimately results in stable pH, which is good for all aquatic life present in the tank.
3. Meet fish kh needs
Every fish species requires a certain kh level to stay healthy in the tank. Neglecting your water source and not checking the kh can be bad for your fish. However, if you check it and get the kh to the necessary level for the fish, then your fish will do okay in the aquarium.
What Causes kh To Drop in Aquariums?
A few factors can cause pH to drop in your fish aquarium, and it often occurs when you don’t monitor the tank enough. As a starter in fishkeeping, this is one thing you should not joke with.
While your fish don’t need 24 hours’ attention, you need to check them and test the water quality for your fish’s general health. Apart from that, the other things that can cause kh to drop in an aquarium and you need to look out for are:
1. Overstocking tank
One way to cause kh to drop in your fish tank is by overstocking the aquarium. When you stock your tank to over 85% capacity, you may have a kh problem.
This will definitely cause unstable water parameters, which will affect carbonate hardness and other chemical imbalances in the tank. When you add too many fish into your fresh water tank, you can expect a pH crash, which you would have to deal with.
2. Absence of routine water changes
Water changes are necessary for your fish’s overall well-being in the tank. Many things in your tank affect water quality, ranging from food and fish waste, algae growth, low kh, increased pH, and other factors.
When you neglect water changes, a lot can happen. For example, bacterial nitrification can cause kh to drop in the tank. However, you can avoid that through water changes.
3. Excess CO2
CO2 is essential for aquariums, no doubt, but it becomes a problem when it’s overdosed. CO2 can dissolve into carbonic acid, resulting in a highly acidic water parameter that eventually causes kh to drop in the tank.
And it gets worse; it causes pH to drop as well.
How To Raise kh in Aquarium
Low kh is highly detrimental to your fish’s health, hence the necessity to fix the issue. You must prevent that from happening by maintaining a balanced and clean aquarium.
You also need to occasionally test the water to check whether the carbonate hardness is at the ideal level for the kind of fish you keep. You would need a test kit to check the water’s kh level.
Some testing kits you can use are:
You need to use the test kit to get the reading for the kh level of your fish tank. If you notice that it is below the recommended one for your freshwater fish tank, you need to do something.
The following are the ways you can raise kh in aquariums:
1. Water change
One of the ways you can raise kh in your fish tank is through water change. When the carbonate hardness is low, you need to replace the water in the tank. This also involves testing your water source because that could be a problem.
If the water source is okay, then you fill up your tank. While at it, you should also maintain your tank and rid it of any dirt or junk. There should be an improvement after this.
2. Baking soda
You can also raise kh in aquariums with baking powder. Good for you if you have some at home; however you need to use it with caution.
Baking soda contains alkaline, which can drastically increase pH if you use too much of it in the aquarium. One teaspoon of baking soda per 50 liters of water is ideal for raising kh.
In addition, you have to be careful not to cause a sudden rise because this can affect your fish. Therefore, ensure you gradually increase the kh and test at intervals for progress.
3. Professional alkalinity buffers
Alkalinity buffers help raise kh and pH levels in fish tanks. These buffers gently and gradually increase kh in water, and they are good for when pH is low.
Furthermore, you need to use this with caution because overdosing the tank with these buffers can make the water hard, which is another problem you would have to deal with. Follow the manufacturer’s instructions and test for kh at intervals as you use them.
Here are a few suggested ones for you:
4. CO2 systems
You can prevent and take care of kh issues in your tank with CO2 systems. This is good for all yeh aquatic life present in your tank, especially the plant since they need CO2 to thrive.
However, you need to be careful with CO2 systems because higher CO2 levels can affect pH and kh levels.
Some of the CO2 systems you can use are:
5. Crushed coral
Crushed coral can help raise kh and keep your fish tank healthy. This is an alkaline buffer supplement that can gradually raise kh and pH.
Crushed coral releases carbonate ions and calcium into the water, which helps raise kh. Pour the coral into a mesh bag and put it in the tank’s filtration system.
You need to check the kh level at intervals and the pH because it can raise the level beyond normal.
Some crushed coral options for you:
6. Dolomite rock
Dolomite rock contains magnesium, carbonate, and calcium, which interact with acids in your aquarium and counters them. This consequently raises pH in aquariums.
However, they may not be very effective if the water pH is very high, so you should check before using them.
Aragonite is similar to crushed coral. It also releases carbonate and calcium but is only different from coral based on its looks. Aragonite consists more of sand-like particles and works similarly to crushed coral.
8. Potassium bicarbonate
Another way to raise the kh level in aquariums is by using potassium bicarbonate. This element can replace baking soda, making it effective for this purpose.
You only need to use about 2.5 to 3.5 grams of potassium bicarbonate in your aquarium to get it to your desired level.
Limestone can also help increase the kh level in your fish tank. It is similar to crushed coral, aragonite, and dolomite. In addition, it also helps to increase pH.
When you use this, you need to keep testing the water to check the pH level, so you don’t raise it beyond normal.
10. Dechlorinated tap water
You can also raise the kh level by using a water conditioner to dechlorinate the water source. You should do this when doing routine water changes.
Use the conditioner in the tap water and let it settle for 24 hours, test it before adding it into the aquarium.
Generally, as an aquarist, you need to ensure that you keep water parameters and quality at the ideal level, which involves regular monitoring and routine water changes. More importantly, you should be able to balance kh, pH, and CO2 in your tank because this will consequently affect your fish, whether negatively or positively.
This is why it is best you know how to raise kh in aquarium without tampering with the others. You should check the water quality as you try any of the methods discussed in the articles for any fluctuation.