Kalkwasser

Kalkwasser (German for “lime water”) or kalk, is a calcium hydroxide solution that is a beneficial additive in reef environments.  It adds buffering capacity to the water neutralizing acids and maintaining a high pH and adds calcium to the benefit of corals.  It is very cost effective and easy to use.  From any online pet supply retailer, one can buy a supply that will last months if not a year, depending on tank size, for around $12.  It is beneficial to use kalkwasser every time evaporated 

water is replaced.  It comes in powder form and a small amount is added to freshwater.  Similar to making a protein powder shake at home, the kalkwasser powder won’t dissolve into the water just by stirring.  It helps if you are able to shake the mixture for about 30 seconds in a container before adding to your tank or sump. 

The benefits and use of kalkwasser were described to Amanda and her parents.  They had a misunderstanding and thought they should use kalkwasser not just when replacing evaporated water, but when replacing ANY water; e.g. a water change.  They mixed their replacement water properly, but then added the designated amount of kalkwasser to the solution before adding it to the tank.  This resulted in a large quantity of undissolved kalkwasser making the tank extremely cloudy.  Luckily there wasn’t any livestock in the tank, and the water parameters haven’t been effected negatively.  The plan to slowly resolve the problem and salvage the water and sand that was already in the tank was to turn off the filtration for short periods, allow the kalkwasser to settle, then siphon it out from the bottom.  This was done about five times total with a great result.  This is a good lesson learned for all.  For more detailed information about kalkwasser, read an excellent article HERE at reefkeeping.com.