On my 265g. F.O. tank, i added calcuim (just a little) and the tank got really cloudy.. the ph dropped and the nitrates went throught the roof. - I pulled my only two fish out of there and did a water change.. a few days the tank settled and the i added the fish back? Now a few weeks later I added more calcuim (a couple of cap fulls) and the tank started to get cloudy.. i quicky added ph buffer and it became clear. A friend of mine told me that the carbonate hardness was high? and it would let the calcium dissolve? Is there any truth to that? and how do I lower the hardness?
WHAT IS CARBONATE HARDNESS
- Thread starter jrwagner
- Start date
Carbonate hardness is due to carbonate/bicarbonate ions, and represents the main 'buffering capacity' of the water, (i.e. its ability to resist pH changes). KH and pH are therefore inter-related: if KH is high, the pH will be very stable (and difficult to alter), if KH is low (e.g. less than 3 degrees KH) then the pH will be less stable.
Carbonate hardness is sometimes referred to as 'temporary' hardness, because it can be removed by boiling, which precipitates the carbonates. The remaining hardness contributed by other salts of calcium and magnesium is then referred to as permanent hardness, or non-carbonate hardness.
Note that a confusing number of units have been used to refer to hardness values, including different English, American, German and French degrees of hardness.
Here's a table of hardness levels:
Carbonate hardness is sometimes referred to as 'temporary' hardness, because it can be removed by boiling, which precipitates the carbonates. The remaining hardness contributed by other salts of calcium and magnesium is then referred to as permanent hardness, or non-carbonate hardness.
Note that a confusing number of units have been used to refer to hardness values, including different English, American, German and French degrees of hardness.
Here's a table of hardness levels:
Dang, LOL beat me to it! Anywho, some more info.....
Carbonate hardness is the result of contact between water (H2O) containing carbon dioxide (CO2) and lime or chalk (CaCO3). Carbon dioxide reduces calcium carbonate to calcium hydrogen carbonate, which imparts carbonate hardness to nearly all fresh waters. In salt lakes, carbonate hardness is partially due to sodium hydrogen carbonate (NaHCO3 ). Many municipal waterworks add chalk or lime to the extremely soft water to prevent corrosion of piping.
The pH value of aquarium water is determined by the ratio of carbonate hardness and carbon dioxide. In most natural waters, the overall hardness consists mostly of cabronate hardness; when it is high, so is pH. When breeding fish, carbonate hardness influences egg maturation, embryo hatching, and the wellbeing of the fry.
Many species have become adjusted to their particular water conditions; under certain conditions, some plants can even utilize carbonate ions as a substitute for CO2. This biogenic declasification can reduce the carbonate hardness of an aquarium over time.
The usual form of nitrate seen in aquaria is nitric acid; this, too can absorb carbonate hardness. If the nitrate content of the water incrases by 22 mg/l, carbonate hardness will be reduced by 1 dKH. In extreme instances, this process can lead to acid fall, a drop in pH so severe that the fish die.
In tanks with good biological filtration, the pH usually remains quite stable, since denitrification daily removes the same amont of nitrate that is present.
Carboante hardness can also be formed in the aquarium. Carbon dioxide fertilizers can dissolve chalk which is present in the substrate or decorations, incresing the hardness. The simpleslt way of increasing the carbonate hardness is to dissolve sodium hydrogen carbonate (NaHCO3 ), more commonly known as bicarbonate of soda, or baking powder. A heaped teaspoon in 100 liters of water increases the carbonate hardness by 3.3 dH. This should not be used in extremely soft water, since bicarbonate of soda contains neither calcium nor magnesium.
Reducing carbonate hardness is most simply accomplished by dilution with distilled or fully desalinated (RO) water, or by filtering the water through peat. Using peat in an aquarium filter for several weeks or more, however, may have the reverse effect, since the material biologically decomposes and releases large amounts of minerals.
References:
Kassebeer, Dr. Gerd. "An Analytical Course for Aquarists," Part III, Carbonate hardness of the aquarium water.
Carbonate hardness is the result of contact between water (H2O) containing carbon dioxide (CO2) and lime or chalk (CaCO3). Carbon dioxide reduces calcium carbonate to calcium hydrogen carbonate, which imparts carbonate hardness to nearly all fresh waters. In salt lakes, carbonate hardness is partially due to sodium hydrogen carbonate (NaHCO3 ). Many municipal waterworks add chalk or lime to the extremely soft water to prevent corrosion of piping.
The pH value of aquarium water is determined by the ratio of carbonate hardness and carbon dioxide. In most natural waters, the overall hardness consists mostly of cabronate hardness; when it is high, so is pH. When breeding fish, carbonate hardness influences egg maturation, embryo hatching, and the wellbeing of the fry.
Many species have become adjusted to their particular water conditions; under certain conditions, some plants can even utilize carbonate ions as a substitute for CO2. This biogenic declasification can reduce the carbonate hardness of an aquarium over time.
The usual form of nitrate seen in aquaria is nitric acid; this, too can absorb carbonate hardness. If the nitrate content of the water incrases by 22 mg/l, carbonate hardness will be reduced by 1 dKH. In extreme instances, this process can lead to acid fall, a drop in pH so severe that the fish die.
In tanks with good biological filtration, the pH usually remains quite stable, since denitrification daily removes the same amont of nitrate that is present.
Carboante hardness can also be formed in the aquarium. Carbon dioxide fertilizers can dissolve chalk which is present in the substrate or decorations, incresing the hardness. The simpleslt way of increasing the carbonate hardness is to dissolve sodium hydrogen carbonate (NaHCO3 ), more commonly known as bicarbonate of soda, or baking powder. A heaped teaspoon in 100 liters of water increases the carbonate hardness by 3.3 dH. This should not be used in extremely soft water, since bicarbonate of soda contains neither calcium nor magnesium.
Reducing carbonate hardness is most simply accomplished by dilution with distilled or fully desalinated (RO) water, or by filtering the water through peat. Using peat in an aquarium filter for several weeks or more, however, may have the reverse effect, since the material biologically decomposes and releases large amounts of minerals.
References:
Kassebeer, Dr. Gerd. "An Analytical Course for Aquarists," Part III, Carbonate hardness of the aquarium water.