[tmz]

Todd,
No it won't affect calcium and alkalinity levels in any direct way since none of the soda lime goes into the water, only the relatively CO2 free air goes to the skimmer air intake. The CO2 is trapped by the oxides in the soda lime. This lowers the level of CO2 in the water compared to a skimmer bubbling in room air with CO2 in it. Less CO2 in the water ,lessens the amount of carbonic acid( H2CO3) formed by some of the CO2 which hydrolizes in water. Less carbonic acid means less H protons which means higher ph. Excess CO2 in the water lowers ph.

White vinegar is a 5% solution of acetic acid(CH3 OOH) which as it breaks down to acetate and hydronium adds H protons to the water lowering the ph which allows more calcium hydroxide to remain in solution For example folks who want to dose more than 2 tsps per gallon can go up to 2.72 tsps per gallon by adding 48ml vinegar per gallon of mixing water . Vinegar also provides an organic carbon source which fuels bacterial growth and possible blooms . For this reason it is generally recommended that anyone spiking limewater with vinegar start at no more than 12 ml per gallon which would only allow an increase in calcium hydroxide to 2.18 tsps per gallon without precipitation.

Limewater is calcium hydroxide(Ca(OH)2 which in water disassociates to Ca(calcium) and oxide. The Hdroxide(O) joins up with CO2 forming CO3(carbonate). Some of the carbonate picks up H+ protons to form HCO3(bi carbonate) . The ratio of carbonate to bicarbonate varies in relation to ph( which is a measure of the number of H protons in the water; more H = lower ph)) . At lower ph there is more bi carbonate since there are more available H protons.So, when you dose limewater(kalk) you create carbonatesome of which transforms to bicarbonte by taking up an H proton.This loers the number of H protons in the water thus raisng the ph . You also deplete CO2 as it is used to form CO3( carbonate) , this also raises ph since there is less CO2 to form carbonic acid( H2 CO3) which is formed when CO2 hydrolizes( CO2 + H2O--> H2CO3).