We changed our method of opening the pool this year. We did not go to the pool store to have our water tested nor to buy chemicals. The result: my wife said that she could not believe how much better the process went this year. Less money spent, less effort, less time required to have a sparking clear pool.
The secret. BBB, home testing, and a little knowledge.
In the past we used hypo to shock the pool. This year we used Wal-Mart bleach. In the past the hypo would cloud the water so that we had a hard time determining if we were making progress. The pH would increase so we were constantly pouring muriatic acid into the water. And running back to the pool store for more acid..
In the past we tried to gage how much shock to use by pool store testing combined with OTO Cl tests, and DPD Cl tests. While we could tell that we were shocking the pool it was difficult to determine if we were making progress killing algae. Of course the pool stores recommended algaecides with their unmentioned side effects. If you have been fighting algae for days it is difficult to not pickup a bottle or two of algaecide just to make sure.
This year we tested the water with the FAS-DPD test. We could accurately measure the Cl level; this enabled us to take the Cl to shock level and hold it there. By the second day the Cl level held so we knew that we did not have to continue adding more Cl. We were done shocking the pool in less than two days; previously we struggled for more than a week.
Last summer I stumbled into a test that proved to me that a pool owner should not rely on pool stores for water testing. Saturday morning we drove to the pool store that we liked and had our water tested. Later in the afternoon we discovered we needed another chemical and we drove to a closer pool store. We had the same water tested again. The water was in a capped bottle and had been kept out of the sun. The second water test was significantly different from the first water test in two levels. I realized then that a pool owner should not rely on a pool store for testing.
The next week I asked the owner of a pool store how they calibrated their testing equipment and how they verified their water testing results. You should have seen the blank look on his face. I decided then to test my water and only have a pool store test the water when I went to the store to purchase muriatic acid or CYA. One Saturday I tested my water and determined that the water was almost in perfect balance except the pH was 7.8. I went to a pool store to purchase muriatic acid and had the pool store test the water. When I received their water test results I burst out laughing. They had changed their computer program to suggest pool owners purchase more chemicals. The computer results listed between $100 and $200 of chemicals that I needed. I asked the owner why not just add a little muriatic acid. He was embarrassed at the obvious over selling and told me that I could ignore the two pages of computer recommended chemicals.
Pool stores printed results give a false sense of accuracy. Using a scanner attached to a computer does not increase the accuracy of a test strip. A computer can print the water test results to three decimal places but still be wildly inaccurate and unreliable. Remember GIGO.
For spring opening we went from one to two weeks of pouring chemicals into the pool and daily brushing to less than two days to open the pool for spring. If you are experiencing pool maintenance problems I suggest the following:
1) Read the articles in the Pool School. Read it, think about it, and learn it. You will know more than many if not most pool store employees.
2) Purchase a good pool water test kit. The test kit should include a FAS-DPD test for Cl and a torpidity test for CYA. The FAS-DPD test enables you to test for FC and CC accurately. Proper CYA level is necessary to minimize costs and problems; test strips do not accurately measure CYA nor is the test reliable. My experience has been most test kits give similar results for TA, CH, and pH. Most pool stores use test strips for their convenience and speed.
3) Use the BBB method.
I now tell other pool owners that they can solve their pool maintenance problems by purchasing their pool chemicals in the laundry isle of Wal-Mart and by testing their own water.