| The kalk powder is denser than the resulting saturated solution when the kalk mixes with the water. The reactors are usually tall enough that they hold a gallon or so of clear saturated solution. If you used up that much solution then you would basically be pushing out the white powder that is in suspension from the mixing. As Reeflady mentioned, the kalk is dripped or added very slowly, thus you would not use up that large of a volume at one time. Additionally you add it sooo slowly that the powder has enough time to settle out of the saturated effluent. This is one of the considerations you need to take into consideration when setting up a proper dosing method with your tank specs. Small sumps that show a little evaporation rather easily can be set up with a float switch and a powerhead to feed it as a little bit of evaporation translates in a big height difference in the water column to activate the float switch. For LARGE sumps or larger sumps without a sectioned pump area, it is safer to use a drip method or a peristlatic dosing pump. |