In 1991, a test pool in Pasadena was plastered by NPC members.

This pool was subdivided using tile into eight different plaster sections. Here is a photograph of one of the sections. The white tile lines are visible at the left and right edges of the photograph.

The test pool was acid started, and then maintained with balanced water for about eight months, followed by aggressive water for about four months. The chemical care was provided by Stan Zielinski (IPSSA).

The pool was then inspected by the NPC. They noted that only two sections out of eight had spots (spot etching). None of the other sections had any spotting.

So what did the NPC announce to the industry about this pool? Nothing. The NPC did not release the results of this test pool and never addressed the interesting facts that indicated something other than water chemistry as causing a few spots to develop in two plaster sections out of eight.

In 1996, about five years later, onBalance went to look at this pool with Stan Zielinski (see him with Doug above). We noted that still only two sections had spots. None of the other six sections of plaster had developed any spots (although one of the other sections had 18-20 calcium nodules). This information was brought to the attention of the NPC, and we asked for a response about their position regarding these results. The NPC refused to address any of the results of this test pool.

Is there a legitimate reason to not conclude anything from these experiments, and allow the results of this NPC experiment to be ignored and discarded?