How can I increase the carbonate hardness?
- Thread starter Lois
- Start date
Can you post your full water parameters including tap water?
Another choice is to use plain, unscented Epsom salt but it is helpful to know your source water parameters for dosing suggestions.
Another choice is to use plain, unscented Epsom salt but it is helpful to know your source water parameters for dosing suggestions.
Epsom salt is magnesium sulfate. it has absolutely no effect on KH (carbonate hardness). It does change GH (general hardness) which is a measure of things like calcium and magnesium in water. I have used magnesium to help make my water harder to simulate the raised GH that one sees during the dry season in seasonal type waters. I have use crushed coral to raise the KH in a tank in which pressurized co2 was injected for plants.
Adding Epson raise GH, adding carbonates and/or bicarbonates raises KH. Crushed coral is calcium carbonate.
Aquarium salt is just salt like you put on your food. It is just a branding trick to make you pay a lot more for sodium chloride. It has little or no place on most FW tanks (African rift lakes is one major exception). On the other hand, a salt water mix contains more than salt just as seawater does. Hardness test kits do not pick up on salt in the water. However salt does affect the conductivity/TDS of water.
In nature one usually finds high GH and high KH together and vice versa. In tanks, things can be different.
Go here and read the sections on Practical Freshwater Chemistry. They are easy to understand. http://fins.actwin.com/mirror/begin.html
Adding Epson raise GH, adding carbonates and/or bicarbonates raises KH. Crushed coral is calcium carbonate.
Aquarium salt is just salt like you put on your food. It is just a branding trick to make you pay a lot more for sodium chloride. It has little or no place on most FW tanks (African rift lakes is one major exception). On the other hand, a salt water mix contains more than salt just as seawater does. Hardness test kits do not pick up on salt in the water. However salt does affect the conductivity/TDS of water.
In nature one usually finds high GH and high KH together and vice versa. In tanks, things can be different.
Go here and read the sections on Practical Freshwater Chemistry. They are easy to understand. http://fins.actwin.com/mirror/begin.html
Sorry about the recommendation for Epsom salt for KH 
, I meant to post that Baking soda (sodium bicarbonate) can be used to raise both pH and KH.
Lois, consider buying the API GH and KH test kits to get a more accurate result than the 5 in 1 test strip.
It would be helpful to know more details on your tank, stock list and why you are considering adjusting your water parameters.
, I meant to post that Baking soda (sodium bicarbonate) can be used to raise both pH and KH.Lois, consider buying the API GH and KH test kits to get a more accurate result than the 5 in 1 test strip.
It would be helpful to know more details on your tank, stock list and why you are considering adjusting your water parameters.
Im only considering it as the test says that it is below the recommended level. Before all my levels were at the recommended level according to the API test, except GH (as we have hard water here).... But now the KH is low and the GH still high. If it doesn't matter, I will leave it.
I may have some baking soda, but how much would you recommend to put in?
I have Mollies, tetras, rams, Cory's, a plec and a catfish.
I may have some baking soda, but how much would you recommend to put in?
I have Mollies, tetras, rams, Cory's, a plec and a catfish.
I wouldn't mess with it honestly.
I keep mostly Lake Malawi and Tanganyika cichlids which like hard and alkaline water which my well water works well with. What I always suggest to someone who has questions about their tap (source) water and thinking of buffering is to use the pH, GH and KH tests and sample their tap water plus leave a sample of tap water out for 24 hours to off gas. Compare the 2 results to see if there is a change in the parameters.
I keep mostly Lake Malawi and Tanganyika cichlids which like hard and alkaline water which my well water works well with. What I always suggest to someone who has questions about their tap (source) water and thinking of buffering is to use the pH, GH and KH tests and sample their tap water plus leave a sample of tap water out for 24 hours to off gas. Compare the 2 results to see if there is a change in the parameters.
Do you have live plants? They can "use up" KH. I've done baking soda ( the kind you cook &/or clean with) but you want to avoid big swings. You may need to add a small amount say, twice a week. Start with a1/2 teaspoon & see what that does to your KH level. Then test every few days to see when you need to add more.
Have you tested your tap water?
Have you tested your tap water?
L
Lois
Did you read that link I posted for you? If so then you should have seen it tells you how much baking soda to use.
The nitrifying bacteria require inorganic carbon. CO2 is inorganic carbon. But so too are the carbonates and bicarbonates and the bacteria can use them as well as can some live plants.
Do what fishorama suggested above and test the KH of your tap water. If it is clearly higher than your tank, then you can pretty much conclude it is getting used up. If you feel compelled to do something to raise your KH, I suggest adding a small bag of crushed coral to your filter. However, water chemistry is not so simple. Your pH is the more crucial factor here.
In water with a higher pH- pushing above 7.0 and towards 8 or higher. The crushed coral will not help much. KH is what holds pH up. In lower pH, under 7 and moving lower, the acid water dissolves the coral putting the calcium carbonate into the water. The calcium part will act to raise the GH and the carbonate acts to raise the KH. The more acid ones water, the faster the coral dissolves. If you only use a small amount in a bag in your filter and your water has a neutral or lower pH, you should see a moderately fast change in the KH. Using a small a,
I would suggest for your size tank that you start with about 1/4 cup of coral in a mesh bag in a filter. Bear on mind that it dissolves so it eventually will be gone. You will need to add more as it gets close to being used up.
The problem you may have is finding crushed coral in smaller amounts.. Not because it is rare but because it is most commonly used in African cichlid tanks as substrate and is usually sold in 15 -25+ lb bags. I bought one about 16 years ago and it will outlast me. These days it may be found in smaller amounts:
https://www.aquariumcoop.com/products/crushed-coral-1-pound-bag
If you have a Petsmart near you: https://www.petsmart.com/fish/decor...in-aquarium-crushed-coral-gravel-5049403.html $13/15 lbs.
Did you read that link I posted for you? If so then you should have seen it tells you how much baking soda to use.
The nitrifying bacteria require inorganic carbon. CO2 is inorganic carbon. But so too are the carbonates and bicarbonates and the bacteria can use them as well as can some live plants.
Do what fishorama suggested above and test the KH of your tap water. If it is clearly higher than your tank, then you can pretty much conclude it is getting used up. If you feel compelled to do something to raise your KH, I suggest adding a small bag of crushed coral to your filter. However, water chemistry is not so simple. Your pH is the more crucial factor here.
In water with a higher pH- pushing above 7.0 and towards 8 or higher. The crushed coral will not help much. KH is what holds pH up. In lower pH, under 7 and moving lower, the acid water dissolves the coral putting the calcium carbonate into the water. The calcium part will act to raise the GH and the carbonate acts to raise the KH. The more acid ones water, the faster the coral dissolves. If you only use a small amount in a bag in your filter and your water has a neutral or lower pH, you should see a moderately fast change in the KH. Using a small a,
I would suggest for your size tank that you start with about 1/4 cup of coral in a mesh bag in a filter. Bear on mind that it dissolves so it eventually will be gone. You will need to add more as it gets close to being used up.
The problem you may have is finding crushed coral in smaller amounts.. Not because it is rare but because it is most commonly used in African cichlid tanks as substrate and is usually sold in 15 -25+ lb bags. I bought one about 16 years ago and it will outlast me. These days it may be found in smaller amounts:
https://www.aquariumcoop.com/products/crushed-coral-1-pound-bag
If you have a Petsmart near you: https://www.petsmart.com/fish/decor...in-aquarium-crushed-coral-gravel-5049403.html $13/15 lbs.
