Hillbilly Hot Tub Posted May 19, 2011 Report Share Posted May 19, 2011 Calcium chloride has a PH of 8-9, how does it not effect the PH when added to the water???? I have always done CH first when filling tubs, and I dont use cheap chemicals, I use 100% calcium chloride, which has a PH of 8-9, which unless there is a chemical reaction when adding to water, would raise the ph??? What am I missing? Quote Link to comment Share on other sites More sharing options...
chem geek Posted May 20, 2011 Report Share Posted May 20, 2011 It has virtually no effect on the pH in a pool whatsoever. The pH of a solution doesn't tell you how much the pH will change when added because solutions that are unbuffered have far less capacity to move pH than buffered solutions. Also, the pH scale is logarithmic and a pH of 8-9 has very little base in it. Finally, that pH amount for calcium chloride is probably for a 1% solution which is unbuffered. 300 ppm calcium hardness (which is ppm calcium carbonate) is equivalent to 0.033% so far less concentrated than a 1% solution. The slightly elevated pH of calcium chloride comes from a small amount of calcium hydroxide that is in some forms of this product and this is mostly unbuffered (though there is a small amount of calcium carbonate in the solution as well). This MSDS for DowFlake shows about 83-87% calcium chloride (anhydrous), 2-3% potassium hydrochloride, 8-14% water (because this product is really calcium chloride dihydrate) and 1-2% sodium chloride. This MSDS for Peladow shows >91% calcium chloride (anhydrous), 4.5% water, 2.5% potassium chloride and 1.5% sodium chloride. This MSDS for Tetra shows 74-100% calcium chloride with possible contaminants of calcium carbonate, calcium hydroxide, calcium oxide, alkali metal chlorides and alkaline earth metal chlorides. Quote Link to comment Share on other sites More sharing options...
Hillbilly Hot Tub Posted May 20, 2011 Report Share Posted May 20, 2011 It has virtually no effect on the pH in a pool whatsoever. The pH of a solution doesn't tell you how much the pH will change when added because solutions that are unbuffered have far less capacity to move pH than buffered solutions. Also, the pH scale is logarithmic and a pH of 8-9 has very little base in it. Finally, that pH amount for calcium chloride is probably for a 1% solution which is unbuffered. 300 ppm calcium hardness (which is ppm calcium carbonate) is equivalent to 0.033% so far less concentrated than a 1% solution. The slightly elevated pH of calcium chloride comes from a small amount of calcium hydroxide that is in some forms of this product and this is mostly unbuffered (though there is a small amount of calcium carbonate in the solution as well). This MSDS for DowFlake shows about 83-87% calcium chloride (anhydrous), 2-3% potassium hydrochloride, 8-14% water (because this product is really calcium chloride dihydrate) and 1-2% sodium chloride. This MSDS for Peladow shows >91% calcium chloride (anhydrous), 4.5% water, 2.5% potassium chloride and 1.5% sodium chloride. This MSDS for Tetra shows 74-100% calcium chloride with possible contaminants of calcium carbonate, calcium hydroxide, calcium oxide, alkali metal chlorides and alkaline earth metal chlorides. Ahhh, I mstill do all the chemicals, then adjust the PH and ALK last, after the tub heats. Just my personal preference i guess. Quote Link to comment Share on other sites More sharing options...
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