Minerals – The Planted Aquarium Water Parameters

by Jun 10, 202010 comments

Every healthy ecosystem requires a balanced environment, including the environment we lived in. Just like we humans and land animals cannot survive breathing polluted air or drinking contaminated water, aquatic life (faunas and plants) will have a difficult time living in sub-optimal water. Of all the balanced factors that go into a successful planted aquarium – the filtration, lighting, CO2 injection, fertilization, substrate – I would insist that the quality of the water used in our planted aquariums may be the most important. In this article, we will be discussing the minerals part of the planted aquarium water parameters.

Table of Contents

Importance of Knowing Good Water Parameters
Minerals
What is Carbonate Hardness?
So Why is KH Important to Your Planted Aquarium if it Still Permits pH Swings?
KH and pH are Directly Proportional?
Why do We Want to Mess with our KH and How Can We Do it Right?
What Should be the Best KH Levels for Our Planted Aquariums?
What is General Hardness?
Too Low?
Ways to Increase
Too High?
Ways to Decrease
Can We Lower pH without changing KH In a Planted Aquarium?
How to Test for KH and GH?
Stressing This Out Again
Conclusion
Closing Remarks

Weekly water parameters tests from the beginning weeks to months of your planted aquarium are critical to making sure that your parameters are in check, don’t let others say otherwise. The way co-hobbyists talk about good water parameters can be confusing at times. Add that to the fact that you may have different water sources and parameters due to your differing location/city, and you may not be able to replicate what works for him/her. That is why every planted aquarium is unique, and you have to find the balance of what you’ve got in hand.

Knowing what makes ‘good water’ for your planted aquarium is critical for maintaining a healthy environment for your fish and plants. It will help us understand the intricacies of a planted aquarium and will arm you with valuable insights on what to do if you notice any problems. Knowing good water parameters even helped me think outside the box, formulate theories, and tested them to see what works and what doesn’t, which I will explain later below.

The planted aquarium water parameters can be further broken down into categories, namely:

Bucephalandra sp

Nutrients

Ammonia/Ammonium

Nitrite

Nitrate

Phosphate

Amano Shrimp

Minerals - You Are Here

Carbonates and Bicarbonates (KH)

Calcium and Magnesium (GH)

My Aquarium Fan for Evaporative Cooling

Environmental Indicators

pH

Temperature

Dissolved Carbon Dioxide

Chlorine/Chloramine

TDS (Total Dissolved Solids)

After we discussed the Nutrients part of good water parameters for our planted aquarium in the last article, we will now be discussing the Minerals part (KH and GH), what are their effects, what happens if you have too much or too low, what can you do if you have too much or too low, how to test them, etc. We will also provide the acceptable water parameter ranges for different types of freshwater planted aquariums near the end of these articles.

Minerals

What is Carbonate Hardness (KH)?

Contrary to popular belief, it is not the pH that determines your water’s softness or hardness. pH is the measure of the acidity and basicity of your water. The range goes from 0 to 14, with 7 as neutral. pH lower than 7 indicate acidity, and pH greater than 7 indicate basic or alkaline water. Like the Richter scale used to measure earthquakes, the pH scale is logarithmic, so a pH of 5.5 is ten times more acidic than a pH of 6.5.

Hardness/softness is the measure of dissolved minerals in the water. But although pH and hardness are different water parameter measurements, they are closely linked to each other.

River and Water Parameters

They are closely linked because dissolved minerals will neutralize the effects of acid entering the water (property of water known as buffering or alkalinity), preventing the pH from swinging. Still, again contrary to popular misconception, this pH swing is not the one that will harm our faunas, which we will discuss further down below.

Examples of these dissolved minerals in our water are carbonates and bicarbonates that can neutralize these acids.

Carbonate Hardness is referred to as KH in short. It is determined by the amount of carbonates and bicarbonates in our water, which, in essence, gives our water the buffering capacity to prevent too large pH swings. But why KH and not CH? Because it came from the German spelling of the words Karbonate Hardness.

You will also hear Carbonate Hardness is the alkalinity of the water. The following terms can be used interchangeably with each other, which all refers to Carbonate Hardness (KH):

  • Alkalinity
  • Total Alkalinity
  • Temporary Hardness
  • Buffering Capacity
  • Acid Neutralizing Capacity (ANC)
Cichlasoma Meeka

Don’t also confuse yourself between alkalinity and alkaline water. They are two different things:

Alkalinity = the measure of the ability of water to neutralize acids (which is the same as Carbonate Hardness KH)

Alkaline = the opposite end to acidity in the pH scale, also known as basic water = alkaline water = water that has a pH level above 7 (neutral)

Hybrid Nature and Dutch Styles Aquacaped by Kristopher Gagarin Philippines

Hybrid Nature and Dutch Styles Aquacaped by Kristopher Gagarin Philippines

Nature Style 12 Gallons Long Aquascaped by Michael Yap Philippines

Nature Style 12 Gallons Long Aquascaped by Michael Yap Philippines

The most common source of acidity in water is dissolved Carbon Dioxide. Carbon dioxide comes from when beneficial bacteria breakdown the wastes in our aquarium and when our faunas respire. Carbon dioxide can also be injected in our planted aquariums via DIY CO2 and pressurized tanks.

So you now know that dissolved carbon dioxide is an acid that contributes to the acidity of our water, and it is constantly produced in our planted aquarium naturally, even without deliberate CO2 injection. But did you know that Nitrites and Nitrates are also acidic (nitric acid)? So we have a lot of acid contributors inside our aquariums.

Gas Bubbles Carbon Dioxide Laacher Lake Germany

If you don’t have a planted aquarium, you don’t have any reasons to inject CO2. Those natural acids produced in a non-planted aquarium I mentioned above will eat away at your KH first before affecting your pH significantly. Think of KH as your protective barrier in a non-planted aquarium. But remember, KH is not permanent, and it can also deplete.

I added some limestone rocks in my 35 gallons planted tank and in my filter since day one, and are the ones giving me the buffering of about 3 dKH. My water source doesn’t add any KH. It is zero. If your existing water source has a KH value in it, you are already replenishing the KH in your tank via water change.

Bayou Marsh

When we inject CO2 in our planted aquariums, KH will not actually prevent the pH from dropping. pH will still drop to an extent. CO2, when dissolved in water, some of it will form carbonic acid through reaction with the water molecule, which lowers your pH. It depends on the rate at which you are injecting CO2 (which depends on your lighting intensity), the injection method (misting via diffusers or 100 % dissolved via reactors), distribution, and how much CO2 is degassed whether you are providing surface water agitation or not.

I am injecting CO2 in my 35 Gallons via a 10 lbs pressurized tank. It is currently set at 2 bubbles per second, and then the method of injection is through misting using an inline atomizer from CO2Art. Then the small CO2 bubbles are distributed by my canister filter’s outtake and with the help of three submersible pumps across the whole tank.

My pH drops from 7.4 to about 6.8 (that will give me about 15 to 20 ppm of CO2) after 2-3 hours of injecting CO2, which is what I am really after (I don’t want to trim plants every week and my lighting is only set to 80 %). It is not really written in stone, but most hobbyists shoot to a 1 pH drop when injecting CO2 (7.4 to 6.4), which approximately gives them about 30 ppm of CO2, which is still far from harming our faunas but will improve the growth of your plants drastically. We will discuss more about CO2 injection in our planted aquariums and the KH, PH, CO2 relationship chart in a future article.

So Why is KH Important to Your Planted Aquarium if it Still Permits pH Swings?

Even though my pH drops from 7.4 to 6.8, no harm is being done to my faunas and to all the co-hobbyist that strive for a 1 pH drop when injecting CO2 to our planted aquariums. Contrary to popular misconception, it is not the pH drop and rise that kills our faunas when injecting CO2. It is when you mess with your KH that will result in large swings of your pH in a short amount of time that will affect our faunas.

Too much CO2 can also kill your faunas, but that is independent of KH and pH. Yes, too much CO2 can make your water very acidic, which will drop your pH. KH value may be untouched. But it is not the severe drop of pH that killed/affected them. It is the toxic CO2 levels.

KH and pH are Directly Proportional?

Yes, they are. As KH rises, so does pH too. As KH lowers, so does pH too.

Always strive for a stable KH, regardless of the current value, don’t mess around with your KH with your faunas still in the tank. If you don’t do it right, that is when you have too large pH swings that will kill your faunas.

For example, I always maintain my planted aquarium to 3 dKH, which gives me a stable pH between 7.2 to 7.4 without CO2 injection base on the API pH test that I am using. During lights on, after 2-3 hours of CO2 injecting, pH drops to about 6.8.

Hardscape Diorama Style During Setup Aquascaped by Pitch Gerald Gingco Loyola Philippines

Hardscape Diorama Style During Setup Aquascaped by Pitch Gerald Gingco Loyola Philippines

Hardscape Diorama Style Done Aquascaped by Pitch Gerald Gingco Loyola

Hardscape Diorama Style Done Aquascaped by Pitch Gerald Gingco Loyola

A KH of 2 dKH will give you about 6.8 to 7.0 pH without CO2 injection. I tried raising my KH to 4 dKH (add 1 dKH) before by adding baking soda (Sodium Bicarbonate – a salt) in my water source (about 1/2 tsp), and it gives me a pH of about 7.8 to 8.0. I bring it back to 3 by just performing weekly water change because my water source is zero KH (diluted).

KH is measured in parts per million (ppm), but I prefer to use degrees of Carbonate Hardness (dKH) because that is the unit used in the testing kit that I am using. 1 dKH is about equal to 17.9 ppm.

Iwagumi Style Setup Aquascaped by Reimond Po Philippines

Iwagumi Style Setup Aquascaped by Reimond Po Philippines

Iwagumi Style Done Aquascaped by Reimond Po Philippines

Iwagumi Style Done Aquascaped by Reimond Po Philippines

Why do We Want to Mess with our KH and How Can We Do it Right?

Here are some scenarios:

1. If your water source is from the tap, we recommend you to test your water source once or twice a month for unstable KH levels. You may be decreasing or increasing the KH in your tank abruptly without you knowing because of fluctuating KH levels from your tap. Don’t trust your city’s water source. You don’t know what they are adding to your water unless you are testing it. This also applies to spring water or deep-well water.

If you are using Purified, Reverse Osmosis/Deionized (RO/DI) Water, or Distilled water, these water sources are known to have zero KH. We recommend at least increase your KH to 1-3 by using KH Booster products or using pure baking soda (not baking powder) or mixing it with chlorine-free tap or deep-well water, or add some crushed corals, seashells, limestones, marble chips in your filter. This is to avoid substantial drops in pH when naturally adding even a small amount of acid in our planted aquariums and for the peace of mind knowing that you have at least a barrier to protect your faunas.

Water Sources

2. If you are keeping Cardinal/Neon Tetras or Discus, while they can adapt and live in medium-hard water to hard water, they are known to be hard to breed in captivity and in hard water (most especially the Cardinal Tetras), which may require you to lower your KH, thus lowering your pH too, and with a certain water temperature to trigger them to breed. There are many ways to increase your KH easily. Still, it is a bit difficult to lower your KH without the unstableness. Do it slow, not abrupt. We will discuss the ways to increase or decrease your KH further down below.

3. Related to number 2, you may want to rescape and change the stocking of your tank from an Amazon Biotope (Discus fish) to a Lake Malawi (Cichlid) Biotope. That is from a low KH of about 3-5, and you need to change it to about 10-18 dKH. Do it slow and not abrupt. If possible, do it without your faunas in your tank. And vice versa. For example, you may want to convert your hard water for Guppies or any live-bearers to a shrimp only tank for Red Cherry Shrimps or the more sensitive Caridina shrimps. Blue Bolt Shrimps (Caridina) requires 1-2 KH to thrive optimally. In comparison, Amano Shrimps and Cherry Shrimps requires 2-4 KH.  Bamboo and Vampire Shrimps can thrive in a wide range of KH.

Discus Fish
Cardinal Tetra Breeding
Butterfly Cichlid
Caridina Shrimp

Were there any times that you tried to lower your pH without injecting CO2, and still, the pH won’t change? That is because of your high KH. It prevents your pH from dropping until it is lowered. Lower your KH first.

What Should be the Best KH Levels for Our Planted Aquariums?

The following chart provides acceptable water parameter ranges for different types of freshwater aquariums and tropical ponds. Please take note that these are just general guidelines for maintaining each specific type of aquariums or ponds. Some species of fish, plants, and invertebrates may have more specific requirements. So please research about the specific faunas needs first.

Please also take note that I already included the other critical water parameters values or ranges. For this part of the article, please check the KH row (you can scroll the table horizontally on mobile devices).

Temperature
pH
Ammonia
Nitrite
Nitrate
Alkalinity (Carbonate Hardness - KH)
General Hardness (GH)
Freshwater Community Planted
76-86 F (24-30 C)
6.0 to 7.5
0
0
less than 40 ppm
3-8 KH
3-8 GH
Freshwater Amazon Blackwater Biotope Planted
74-86 F (23-30 C)
4.5 to 6.5
0
0
less than 40 ppm
4-8 KH
3-8 GH
Lake Malawi African Cichlids (Scarcely Planted)
72-84 F (22-29 C)
7.5 to 8.8
0
0
less than 50 ppm
10-18 KH
12-20 GH
Freshwater Clearwater South American Biotope Planted
74-78 F (23-26 C)
7.0 to 7.5
0
0
less than 40 ppm
4-8 KH
3-8 GH
Tropical Pond Planted
70-86 F (21-30 C)
7.0 to 7.5
0
0
less than 40 ppm
4-8 KH
4-12 GH

What is General Hardness (GH)?

Many beginners often confuse themselves with Carbonate Hardness (KH) and General Hardness (GH) when they hear them for the first time. They both have hardness in the name, after all, but they measure different water parameters:

Carbonate Hardness (KH) – the measure of carbonates and bicarbonates dissolved in water.

General Hardness (GH) – the measure of magnesium and calcium ions dissolved in water plus trace amounts of other minerals.

When fish are said to prefer “soft” or “hard” water, generally, it is GH (not KH) that is being referred to. But some fish species need specific pH (which is directly proportional to KH) and GH to thrive and breed, so please research first on the needs of the faunas that you want to keep.

The Water is Super-saturated with Calcium Carbonate forms Travertine - a form of Limestone in Pamukkale Denizli Southwestern Turkey
Salt and Magnesium Deposits

Calcium is essential for the neurological functioning of our faunas. Freshwater snails and shrimps need calcium to grow their shells. On the other hand, magnesium is an important nutrient for the development of bones for our fish and is vital for biological functions.

If someone says, “I have very hard water where I live,” he or she is talking about GH.

In my case, I always maintain my GH from 5-7 dH, which means degree hardness for the unit of GH.

Please see the table again above for GH ranges suitable for different types of freshwater planted aquariums.

Please see the table below for the GH Characteristics of Water (you can scroll the table horizontally on mobile devices).

Range (dH)
0-4
4-8
8-12
12-18
18-30
Beyond
Range (ppm)
0-70
70-140
140-210
210-320
320-530
Characteristic
very soft
soft
medium hard
fairly hard
hard
very hard

In most cases, when a waterway has high GH, it will also have high KH (this is hard water). This is usually the case if the location has limestone aquifers. An aquifer is a body of permeable rock underground (such as limestone) which can contain or transmit groundwater. Limestone contains Calcium Carbonate (CaCO3), which, when dissolved in water, increases both the GH (calcium part) and KH (carbonate part).

But as with all things, however, there are exceptions, and it is possible to have different results once we add the pH in the equation to form the Bermuda Triangle of water parameters (KH, pH, and GH). For example, the water that I am using is borderline softwater (3 dKH and 5 dH), but my pH is alkaline 7.4. Another example is the Malawi Lake in East Africa. The water is pretty much alkaline (pH 7.5 to around 8.8) yet has relatively soft to medium-hard water. And vice-versa, you can have a low ph (acidic), and it is still hard water (low KH and high GH).

Hard water can also be high in KH and low in GH and vice versa.

Limestone Terraces

Too Low?

So you found out after testing that your KH or GH is zero or very low, and you want to raise it a bit? Here are some of the methods to increase one or the other or both. As always, take it slow when using commercial buffers and baking soda, don’t try to increase your KH from 0 to 5 in one go. This will shoot your pH from about 6.0 to 8.0 +, for example (which means it’s 100x more alkaline than before in a very short amount of time, remember pH scale is logarithmic – 2 points swing – x10 x10), your faunas will not have any chance to adapt). Just go with increments of adding 1 dKH every 2-3 days and monitor your KH, GH, pH, and your faunas. If possible, don’t do this with your faunas in your tank, do this from the start-up.

Ways to Increase

  • Water Change – if your water source has some KH value above 4 dKH, then a weekly water change will replenish the depleted KH. Don’t forget to maintain your tank by performing a vacuum of the substrate and cleaning your glass.
After Water Change by Ayong Go Philippines

After Water Change by Ayong Go Philippines

  • Alkalinity Buffers (for KH) and/or GH/KH Boosters in one – manufacturers such as Seachem and API produce their own line of alkalinity buffers and GH/KH Boosters. Just follow the instructions depending on your tank volume to achieve the desired KH and GH levels. Seachem even has Alkalinity buffers for specific kinds of fish, such as Goldfish, Arowana, Discus, Lake Malawi Cichlids, and Lake Tanganyika Cichlids.
  • Minerals that can raise GH without touching KH are minerals that contain calcium and magnesium but no carbonates and bicarbonates such as Calcium Sulphate and Magnesium Sulphate.
  • Consequently, minerals that raise KH without changing GH are minerals that contain carbonates/bicarbonates but with no calcium and magnesium, such as the Pure Baking Soda (Sodium Bicarbonate) mentioned below and Potassium Carbonate.
  • Use some Limestones – these limestones added stable  3 dKH of carbonate hardness and 3 dH of general hardness to my planted aquarium. The water source I used for water changes contains 0 KH and about 0 dH. I usually add about 2 GH every water change using a GH booster for my shrimps and snails.
Limestones in my 35 Gallons that provides 3 dKH Buffering and 3 dH General Hardness

Limestones in my 35 Gallons that provides 3 dKH Buffering and 3 dH General Hardness. I always add another 2 dH General Hardness every Water Change for my Shrimps and Snails using a GH Booster

  • Crushed Corals/Seashells – it contains calcium carbonates, which will raise both your KH and GH through the reaction to the acids produced in our tank. It will release calcium and carbonates. It has regulating features too. Once your pH rises due to higher KH, the crushed corals won’t release as many minerals as before. You can put them in your filter as filter media or as part of your substrate. In a planted aquarium, though, crushed corals seem out of place as a substrate and non-functional/non-beneficial for planting, so you can place it in the bottom when you layer your substrate.
  • Dolomite Rocks – is a calcareous rock consists mainly of calcium, magnesium, and carbonate. It has regulating features too, like the crushed corals. Both GH and KH will be increased once the acid reacts, releasing all these minerals to your water column.
Crushed Corals Sand
Crushed Seashells
  • Pure Baking Soda (Sodium Bicarbonate) (not baking powder) – using leveled teaspoon measurements requires me about 1/2 tsp of pure baking soda to add 1 dKH to my 35 gallons planted aquarium making it to 4 dKH. I did this during water change (because I am only aiming for plus 1 dkH). I dissolved the baking soda in my 5 gallons water container first for water change (don’t pour the baking soda directly in your tank). Please see the table below so you can calculate the needed teaspoon for your given tank volume in gallons. Divide your tank volume in gallons to 52.84. The result will be the amount of leveled baking soda in your teaspoon to bring your KH to plus 1 dKH.
Teaspoon (tsp)
1/8
1/4
1/2
Gallons
6.65
13.21
26.42
Resulting KH
1 dKH
1 dKH
1 dKH
Baking Soda
  • Calcium Carbonate – to increase both GH and KH, and if you don’t want to add Crushed Corals or Dolomite Rocks as part of your substrate or you have no room anymore in your filter, and you want to make the process controllable, you can add calcium Carbonate. 1/2 teaspoon for every 13 US gallons will yield about 1 dH (GH) and 1 dKH (KH).

Too High?

    Very high KH may not be suitable for the species of fish and plants that you want to keep, plus it can reduce the effectiveness of acid buffers. Very high KH can essentially soak up carbon dioxide. It will bind to the CO2 molecules in a way that prevents the plants from using it. Carbonates such as calcium carbonates from a high KH will cause clogging of heaters and pump impellers in your filter and will leave mineral deposits in your aquarium glass (this also applies to very high GH, remember the calcium part?).

    To expand to the issues with very high KH regarding the livestock and plants you want to keep, those so-called ‘very soft water plants’ like most plants in the Eriocaulaceae family, Tonina, Syngonanthus are actually sensitive to high KH and not on GH. Most other plants can thrive over a wide range of GH than KH.

    Nature Style Aquascaped by Ridgid Portajada Philippines

    Nature Style Aquascaped by Ridgid Portajada Philippines

    It’s more of a spectrum of hardness than a clear distinction between hard and soft water plants. Most plants that do well in hard water are also fine in softer water, while the reverse is mostly not true. For beginners, we won’t recommend for now keeping the most sensitive and very demanding plants with CO2 and lighting, those that thrive in very soft waters such as most of the family members of Eriocaulaceae species, Tonina Fluviatilis, Syngonanthus species, etc.

    As for livestock, most commercially available fish species can live in a surprisingly wide range of GH and KH, while some may not necessarily breed and need very specific KH and GH along with water temperature and pH. Please research the needs of that specific fish if you want to design your planted aquarium based on the faunas you want to keep.

    Ways to Decrease?

    As I mentioned earlier, stable KH keeps your pH from wildly swinging.

    But what if your water source has too high KH resulting in too high pH not appropriate for your fish.

    Well, to lower your pH, you first have to lower your KH. While increasing GH or KH is an easy task and easy to screw up too (that is why the friendly reminder to slow down earlier), lowering GH or KH or both is somewhat difficult.

    Nature Style Aquascaped by Dah Real Philippines

    Nature Style Aquascaped by Dah Real Philippines

    • Acid Buffers – you can use Acid Buffer products such as from Seachem, which converts your KH into Carbon Dioxide, lowering KH, thus lowering your pH too. As I always said, go slow! We only recommend using this on planted aquariums as plants will use up the carbon dioxide. When misused by rushing or overdosing, these products will result in plummeting pH in a very short amount of time, plus a bunch of dead fish. And if used directly to your planted tank, it will result in an excess by-product of CO2 may fluctuate your CO2 levels during photoperiod, which will introduce a new set of problems, for example, algae bloom. Some algae species will love you if you have fluctuating levels of CO2, like Black Beard Algae (BBA) and Staghorn Algae.
    Seachem Acid Buffer

    Seachem Acid Buffer

    • Dilute your high KH and GH water source with RO/DI Water – both of these water purifying systems can create pure water with no KH. To determine the desired ratio, use your GH/KH test kit, start with a 50:50 mixing ratio (50 % chlorine-free tap water or deep-well and 50 % RO) and test the resulting GH and KH levels. The only downside is the start-up cost for a Reverse Osmosis system, but if you already have an existing RO system for your drinking water, then you can certainly use it. Installing an RO system not only for our planted aquarium but for your drinking water as well will save you money in the long run. The goal is to decrease your GH and KH to the desired lower levels after determining the correct ratio.
    Reverse Osmosis Water Filtration System

    Reverse Osmosis Water Filtration System

    • Using Indian Almond Leaves – you can use Indian Almond leaves to lower your KH and thus your pH too. As the leaves breakdown in your tank, they release tannins (organic acids). These tannins will eat away at your KH. The only downside is that Indian Almond leaves will gently lower your water’s KH and pH (slow). If you have a very high KH, you will hardly see any difference at all. Other tannins-releasing botanicals are Guava Leaves, Amber Cones, coconut Husks, Savu Pods, Mariposa and Tapete Pods, etc.
    Using Talisay-Indian Almond Leaves Blackwater Tank Aquascaped by Lao Ricci Philippines

    Using Talisay-Indian Almond Leaves Blackwater Tank Aquascaped by Lao Ricci Philippines

    • Peat Moss – Peat is dried and chopped peat moss. It can lower KH, thus your pH and GH as well. You can put it into a mesh bag and place it in your filter. Like the tannins-releasing botanicals mentioned above, it will release tannins into your water and can lower your KH and pH a bit. Peat can be expensive in pet shops, or you can source your Peat in gardening shops, but make sure it has no chemicals added to cut down on molds, which can kill your fish. Other drawbacks are peat can easily clog in your filter and can cloud your water. Third is the amount of peat needed to soften your water effectively is difficult to estimate. 
    Peat Moss

    Plus, like the Indian Almond Leaves, if you have very high KH or GH or both, you will hardly see any difference at all. Another advice that I can give to use Peat Moss for your planted aquarium effectively is to treat your water outside the tank beforehand and have it ready for the next water change. You can do this by using water storage containers, depending on how much water you are using during water change. Put the peat moss in a mesh bag and put it in the container with the water. You can stir the water every now and then, or you can just use a sponge filter to aerate it for one week, just in time for the water change.

    Can We Lower pH without changing KH In a Planted Aquarium?

    Yes, and I already mentioned it earlier. Injecting CO2 to your planted aquarium will lower your pH without affecting your KH.

    It is not really written in stone, but most hobbyists shoot to a 1 pH drop when injecting CO2 (7.4 to 6.4, for example), which approximately gives them about 30 ppm of CO2, which is still far from harming our faunas but will improve the growth of your plants. We will discuss more about the benefits of CO2 injection in our planted aquariums in a future article. The KH, PH, CO2 relationship chart to determine the concentration of dissolved CO2 in your water is discussed in this article.

    My Pressurized CO2 Injection Setup 2 BPS

    How to Test for KH and GH?

    I personally use the API KH and GH Test Kit. For my needs, it is cost-effective and accurate enough. It is a complete kit already containing 2 liquid bottles solutions for KH and GH and two test tubes. Just follow the instructions.

    API KH and GH Test Kit

    Update 4/14/2021: I tried to experiment since January 2021 to lower my KH from 3 to 1 and GH from 5 to 3 to achieve the 1 pH drop (30 ppm) concentration of dissolved CO2 and less than 100 TDS. Those are the only things that I changed. While I was able to achieve my goal, I notice that some of my Bucephalandra species suffered. Incomplete, deformed, lots of holes in the leaves manifested in them. 3 weeks ago, I started to gradually increase my KH and GH back to where I maintained them before (3 dKH and 5 dGH – 1-degree increase per water change). I notice immediately this week (4th week) improvements in my affected Bucephalandra species.

    When you change a water parameter in your planted tank (whether you are experimenting, finding the balance, or trying to fix something), it may take weeks to months before you can notice any results. This hobby is not always about immediate results. You have to have a lot of patience.

    Stressing This Out Again

    I want to stress again. Every planted aquarium is unique. What worked for others may or may not work for you. We all have a differing degree of planting, tank sizes, water parameters, water sources, stocking, maintenance schedules, lighting (intensity and spectrum), injecting co2 or not, filtration, aeration, substrates, even external factors like extreme weather conditions and ambient temperatures, etc. it is up for the hobbyist to find the balance of all these factors.

    You can also ask for help from others who are willing to help and have the experience. A sensible co-hobbyist will ask some questions first before jumping to conclusions (even if he had the same symptoms before) like what is your water parameters, how old is your tank, did you perform any tank cycling, or do you even know what tank cycling is, what did you changed before the problem happens, what is the size of your tank, filtration used, the substrate used, how is your stocking, your feeding schedule, and maintenance, to name a few.

    From your answers, he may be able to create a hypothesis and test it. He may ask additional questions to prove his theory further until you both reach a conclusion and resolve the problem.

    Conclusion

    Carbonate Hardness (KH) goes with lots of names, but they mean the same thing.  It is the amount of carbonates and bicarbonates in our water, which, in essence, gives our water the alkalinity/buffering capacity to prevent too large pH swings. Although it still permits pH drop when injecting CO2 (it eats your KH away slowly), it is when you mess with your KH that will result in large pH swings. So always strive for a stable KH, but we recommend having at least 1 dKH. Think of your KH as a protective barrier or a sponge, acids naturally produce in your planted aquarium, and injecting CO2 will eat away at your KH first or absorb them first like a sponge before affecting your pH. But like a sponge, it has limited absorbing capability, KH depletes as well, and you have to replenish it.

    General Hardness (GH) is the amount of dissolved calcium and magnesium in your water. When fish are said to prefer “soft” or “hard” water, generally, it is GH (not KH) that is being referred to. But some fish species need specific pH (which is directly proportional to KH) and GH to thrive and breed, so please research first on the needs of the faunas that you want to keep.

    Calcium is essential for the neurological functioning of our faunas. Freshwater snails and shrimps need calcium to grow their shells. On the other hand, magnesium is an important nutrient for the development of bones for our fish and is vital for biological functions.

    We also discussed the many ways to increase or decrease your GH and KH and the scenarios you would want to do that, but as I always said, take it slow.

    Want to Explore More?

    Nature Style 'Nature's Stump' Aquascaped by Matthew Manes Philippines

    Planted Aquarium Galleries

    Here on this page, you will find the planted aquarium galleries of the creative creations of Filipino Aquascapers featured on this website. You will also find the timeline photos of some aquascapes from the beginning to the current state. To start off with, here is the Evolution of my Planted Aquarium which showcases all the events that happened with my tank, some of the insights that I learned along the way, and all my ‘ups’ and ‘downs’ in keeping this planted aquarium at my terrace.

    Using a Trickle Filter Aquascaped by Jei Joaquin Philippines

    Trickle Filters – Types of Planted Aquarium Filters

    The trickle filter concept is to expose the water to as much air as possible, providing more dissolved oxygen. This will make your biological filtration very efficient and far better than other filters. If you can remember, your biological filtration’s efficiency in converting harmful substances (Ammonia and Nitrites) in your water into a less harmful form (Nitrate) depends on the amount of their food and oxygen in the water.

    Low Iron Glass and Clear Glass Comparison

    The Right Material for Aquarium Tanks

    Have you ever wondered what types of glass are used in building our Aquariums, or are there any other materials that we can use? In this article, we will be discussing the right material for aquarium tanks.

    After - Jungle Style Aquascaped by Fritz Rabaya Philippines

    Jungle Aquariums

    Many of the hobbyists worldwide refer to the Jungle Style separate from either Nature or Dutch styles of aquascaping. We can even consider the Jungle style a sub-type of the Nature style.

    The only difference is the wild, untamed (no trimming here, well, you can if you choose to do so) look. It is the complete opposite of the Dutch style, more organized, and looks like a conventional tulips garden.

    My 3rd Re-scape

    The Fastest Method – How to Cycle a Planted Aquarium

    We already discussed the fastest way of cycling your newly planted aquarium. That is to use your old filter media, gravel, soil, hardscapes, and even part of the old water from your old aquarium to your newly planted aquarium.

    Closing Remarks

    I hope you enjoyed this article. If you have additional questions or want to share your experiences with these minerals in your planted aquarium, please leave a comment below. Next, we will be discussing the Environmental Indicators part of water parameters in our planted aquariums.

    10 Comments

    1. Oscar

      Helooo over there, a big thanks to you for sharing this insightful and educational piece on the topic titled; the planted aquarium water parameters minerals.. This is indeed educating, now i know why KH Important to Planted Aquarium even when it still permits pH swings.. I  have really learnt a lot from in here. I really find this article fascinating so am definitely going to visit this site some other time. 

      Reply
      • Lemuel Sacop

        Hello Oscar,

        Thanks again for visiting my site and the appreciation about this article. Please come back more articles coming soon.

        Reply
    2. Alejandra

      Thanks so much for sharing great information about water parameters-minerals for the planted aquarium.

      I’m a mom of three boys and they love to have an aquarium at home, our fight is always about how to keep the aquarium in its best so fishes can live in a good environment.

      I must say we are just beginners and as we were looking for some information, we found today your article, we already saved it on our Pinterest board as we are sure we’ll be back to read it again.

      You share in your article great information about how to keep an Aquarius on its best, we read it, we got some notes and we have a start where we can start!

      Reply
      • Lemuel Sacop

        Hi Alejandra,

        Thanks for sharing your experiences with your boys and your appreciation about this article. Looking forward to seeing your first planted aquarium at home.

        Reply
    3. edahnewton1

      Hey nice article you have there, your thoughts are indeed invaluable. It is important to note that most aquarium buffering capacity test kits actually measure KH. The larger the KH, the more resistant to pH changes your water will be. A tank’s KH should be high enough to prevent large pH swings in your tank over time. Keep the good work, warm regards

      Reply
      • Lemuel Sacop

        Hi Edahnewton,

        Thanks for coming back! Indeed KH and GH is so important.

        Reply
    4. osei kwame

      Hello,
      Thank you for this wonderful piece of article indeed it’s full of information and education. My uncle use to have aquarium in his house but in no time it got disappeared. I have now seen why he couldn’t keep it for long, I believe He will really love to read this guidelines over and over again.
      Thank you once again for sharing this educative information

      Reply
    5. Skuchmane

      hellooo dear, wow what an amazing conetent you have here, i was actually doing some research online when i saw your post, it really is amazing to see such post here, your site is plain and simple easy to understand and navigate, i already saved these post so as to come back fot future refrencing, thanks alot for the info

      Reply
    6. Steviejohn41

      Hello there, This is an amazing and that you have got here. I enjoyed going through this article here on your website, you have mad me understand how to go about preserving and maintaining my aquarium. I have learnt a lot for this article, and I am grateful to have to found this here.

      Thanks for sharing this informative article with me.

      Reply
    7. evansese

      hello Sacop,
      what a fascinating and informative article you have on ; the planted aquarium water parameters minerals.. This is indeed
      educating, now i know why KH Important to Planted Aquarium even when it still permits pH swings.. I  have really learnt a lot from in here. I really find this article fascinating and I look forward to share it on my blog so that every other blogger could also get the knowledge of the planted aquarium water parameters…

       

      Reply

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