Calcium leaching from grout.

[waterbear]

Hi, Denny,

Two thoughts looking at your posts.

You said you add acid to keep your pH around 7.4. Does it rise pretty much on it's own? If so, do you think it has ever slipped up a little too high? If its gotten up around 8 or so, that is probably enough to cause some scaling.

Secondly, I don't understand your FC and CYA results. FC should be in whole numbers and CYA typically is not defineable in less than increments of 10...10, 20, etc.
Not necessarily, These sound like pool store numbers and if they are from a testing setup that uses a colorimeter such as the LaMotte Waterlink it is very possible for the meter to read differences in color or turbidity that the human eye cannot distinguish. The accuracy of these numbers would depend on how accurately the meter is calibrated. Drop based test kits are excellent but if you want to spend the money on instrumentation it IS possible to get more accurate results. Colorimeters and turbidity meters are standard laboratory equipment. Using a colorimeter to read a wet cell (such as a DPD test) is going to be much more accurate than comparing the colors on a comparator block with the human eye.

I know that your question was about scaling but you'll probably need to run your FC up around 6-9ppm with a CYA of 80 for it to be effective.

Dave S.

One other thought...might you have a SWG in the system? If so it might not be scale at all but salt deposits from evaporation.