The relationship between dKH and Ca++
Question:
I cannot seem to get my dKH under control and my calcium level remains around 280 to 300 ppm all the time, regardless of what I do. I add limewater but it does not increase the calcium level at all. My KH runs around 10 or sometimes a little higher. My pH goes from 8.0 to sometimes as high as 8.2 or 8.3
Answer:
The reason the calcium concentration does not rise is probably due to the high KH you are experiencing in the aquarium. High KH levels (dKH or alkalinity or buffer) work against a high calcium level. When KW is added to water that has lots of buffering, the chemical reaction produces calcium carbonate (a white powder) that does not dissolve in your aquarium water.
When the KH is real high and you add KW you may even experience what is called a "calcium fall-out". This results in white powder settling on all the rock or, in major fall-out cases, all the tank panes and anything else in the aquarium being covered by a very thin layer of calcium carbonate. This includes the inside of tubing and pipes used in filtration component attachments. Major fall outs are rare but can happen if you had too much KW at one time and the tank has a high dKH. In most cases only white powder is seen, or in even less significant cases the water may get cloudy. This is due to small amounts of calcium carbonate floating around in the water and clouding it.
In the process of the formation of calcium carbonate, the calcium you add combines with carbonates in the tank and is not available to corals. The bioavailable calcium level in the aquarium is low.
To solve the problem and raise the calcium level (concentration) the dKH needs to be lowered. This is done in various ways. Below are just two:
-Add water containing CO2 to the aquarium. Selzer or mineral is such a type of water because they both contain carbon dioxide. Carbon dioxide forms carbonic acid when it is added to water. The acid reduces the buffer. When the buffer falls the dKH is lower. Add small amounts only in the beginning and test your dKh about 15 or so minutes after adding it. In the beginning the difference may not be large but, as you continue to add it, the dKH will drop. Checking is important because as the dKH drops, the effect of the mineral or selzer water will become greater (meaning the pH and the dKH will drop more for the same quantity of such water added). Make sure when using this method that you check your pH and your dKH regularly, at least each time you add the water and more often if you can. This will prevent the dKH from falling too low (and the pH too).
-Make water changes with prepared water that has a dKH lower than the one in the tank. Sometimes to achieve this it is necessary to reduce the hardness of the water you use before adding the salt. This can be done by adding water as described above, or a real small amount of muriatic acid.
Although it can theoretically be done, adding diluted muriatic acid in real small amounts to the tank directly, is not recommended because of the dangers involved. Indeed, a small overdose could cause a rapid fall of the pH and great stress to the animals. Muriatic acid is a diluted form of hydrochloric acid but is still very acidic and can affect the pH a great deal and rapidly. Unless you are familiar with how to use this acid, it is recommended that you do not add it directly to the sump or tank. The danger of overdosing is too great. Additionally, when you handle muriatic acid you need to be extremely careful as acid burn will occur if you get any on your hands. If you get it on your clothes you will burn holes in them. If some of it drops on your carpet or parquet, damage to them will occur as well. Be extremely cautious and careful when using muriatic acid.
As you continue the addition of water that contains carbon dioxide the dKH will decline and the calcium level will start to increase. It is best to monitor the three levels necessary to know what is going on:
-pH
-dKH
-calcium
When you do so, you gain control over the entire process and do not risk making changes too rapidly. Too rapid changes affect the animals negatively and cause stress. Stress leads to disease and possibly parasitic infestations. Avoid stress at all costs.
Question:
I cannot seem to get my dKH under control and my calcium level remains around 280 to 300 ppm all the time, regardless of what I do. I add limewater but it does not increase the calcium level at all. My KH runs around 10 or sometimes a little higher. My pH goes from 8.0 to sometimes as high as 8.2 or 8.3
Answer:
The reason the calcium concentration does not rise is probably due to the high KH you are experiencing in the aquarium. High KH levels (dKH or alkalinity or buffer) work against a high calcium level. When KW is added to water that has lots of buffering, the chemical reaction produces calcium carbonate (a white powder) that does not dissolve in your aquarium water.
When the KH is real high and you add KW you may even experience what is called a "calcium fall-out". This results in white powder settling on all the rock or, in major fall-out cases, all the tank panes and anything else in the aquarium being covered by a very thin layer of calcium carbonate. This includes the inside of tubing and pipes used in filtration component attachments. Major fall outs are rare but can happen if you had too much KW at one time and the tank has a high dKH. In most cases only white powder is seen, or in even less significant cases the water may get cloudy. This is due to small amounts of calcium carbonate floating around in the water and clouding it.
In the process of the formation of calcium carbonate, the calcium you add combines with carbonates in the tank and is not available to corals. The bioavailable calcium level in the aquarium is low.
To solve the problem and raise the calcium level (concentration) the dKH needs to be lowered. This is done in various ways. Below are just two:
-Add water containing CO2 to the aquarium. Selzer or mineral is such a type of water because they both contain carbon dioxide. Carbon dioxide forms carbonic acid when it is added to water. The acid reduces the buffer. When the buffer falls the dKH is lower. Add small amounts only in the beginning and test your dKh about 15 or so minutes after adding it. In the beginning the difference may not be large but, as you continue to add it, the dKH will drop. Checking is important because as the dKH drops, the effect of the mineral or selzer water will become greater (meaning the pH and the dKH will drop more for the same quantity of such water added). Make sure when using this method that you check your pH and your dKH regularly, at least each time you add the water and more often if you can. This will prevent the dKH from falling too low (and the pH too).
-Make water changes with prepared water that has a dKH lower than the one in the tank. Sometimes to achieve this it is necessary to reduce the hardness of the water you use before adding the salt. This can be done by adding water as described above, or a real small amount of muriatic acid.
Although it can theoretically be done, adding diluted muriatic acid in real small amounts to the tank directly, is not recommended because of the dangers involved. Indeed, a small overdose could cause a rapid fall of the pH and great stress to the animals. Muriatic acid is a diluted form of hydrochloric acid but is still very acidic and can affect the pH a great deal and rapidly. Unless you are familiar with how to use this acid, it is recommended that you do not add it directly to the sump or tank. The danger of overdosing is too great. Additionally, when you handle muriatic acid you need to be extremely careful as acid burn will occur if you get any on your hands. If you get it on your clothes you will burn holes in them. If some of it drops on your carpet or parquet, damage to them will occur as well. Be extremely cautious and careful when using muriatic acid.
As you continue the addition of water that contains carbon dioxide the dKH will decline and the calcium level will start to increase. It is best to monitor the three levels necessary to know what is going on:
-pH
-dKH
-calcium
When you do so, you gain control over the entire process and do not risk making changes too rapidly. Too rapid changes affect the animals negatively and cause stress. Stress leads to disease and possibly parasitic infestations. Avoid stress at all costs.
