I would like some help in identifying some possible sources of acid demand in my pool. I have a salt pool with a SWCG. First my most recent numbers:
I have installed an acid feed pump that maintains the pH more or less constant. Anyway I am adding about 32 oz of 31% acid per week. Some sources of acid demand that I know of:
1. CO2 out gassing. This is a possibility. However my TA has not changed 10 ppm in over a month. It is my understanding that CO2 out gassing at a constant pH will tend to decrease the TA. Using my Colorq it appears that the TA has changed by less than 5 ppm in a month.
2. Plaster curing. Another possibility. However the pool was filled at the end of October. It is now August so the plaster is about 10 months out. I would expect that the acid demand from curing plaster to be rather small.
3. Rain. I live in west central Florida. In the summer we have very high rainfalls. I am pumping out 1 to 2 inches of water from the pool each week. I don't know what effect this would have on the acid demand, but is causing me to add salt and CYA
I am open to any more ideas.