YAY! I love limewater threads!
Questions What will this do??? Kalkwasser will raise your pH level, raise your Calcium level, and raise your Alkalinity level.
How many of you do it??? I used to dose all of my tanks, when I had tanks.
Limewater (also known by the German term kalkwasser) can be made by dissolving either calcium oxide (CaO, also known as quicklime) or calcium hydroxide (Ca(OH)2, also known as lime or hydrated lime) in water.3 When calcium oxide is used, it hydrates to Ca(OH)2 on contact with water:
(1) CaO + H2O à Ca(OH)2 + heat
Consequently, there is little difference between using CaO and Ca(OH)2 except that CaO gives off a significant amount of heat when it hydrates. When these materials dissolve, they dissociate to calcium ions (Ca++) and hydroxide ions (OH-).
(2) Ca(OH)2 à Ca++ + 2OH-
Limewater actually contains a substantial amount of partially dissociated, but fully dissolved, calcium monohydroxide:
(3) Ca(OH)2 à CaOH+ + OH-
The calcium monohydroxide ion comprises about 25% of the total calcium at the pH of saturated limewater (pH 12.4).4
http://www.advancedaquarist.com/issues/may2003/chem.htm
So, basically, when you dose kalkwasser early in the mornings, you should have a low pH in your aquarium. By slowly dosing kalkwasser throughout the day, you keep your pH up and stable, and you also increase your alkalinity level. You also raise your calcium and alkalinity in equil parts.
If your alkalinity is low, and you start to raise your calcium, but the calcium level is too high and your alkalinity is too low, you will see some calcium precipitate out when you dose the aquarium (little white flaky chunks.)
That is why you should increase your alkalinity to match your calcium level before you begin dosing kalkwasser.
To mix kalkwasser, you should add NO MORE than two tablespoons per gallon. On your first dose, you should only use about 1/4 tablespoon per gallon until you see a gradual rise in the calcium and alkalinity of your water column. After one week of dosing 1/4 tablespoon, you can increase it to 1/2 tablespoon per gallon the next week and then gradually increase it by 1/4 tablespoon until you can get to the 2 tablespoon mark.
The reason to slowly increase the amount of kalkwasser that you have used is to ensure that you do not pH shock your fish and corals. Adding too much limewater at a time will increase the pH too sharply, causing problems.
There is also another problem that I have come across when using kalkwasser if you dose only six days a week, your pH will drop on the seventh day. That is why, on the seventh day you should add a marine buffer to your aquarium and not dose your tank with kalkwasser. The reason for adding the pH buffer is that your aquarium becomes dependant on the additional pH that is being added to your tank.
Dosing kalkwasser doesn't have to be difficult - you just have to read and research a little bit.
