Oh sorry...
Kim from OnBalance was in town and stopped by. He feels that it is possible that a poor mixture that was used, creating some shrinkage, which lead to cracks in the plaster, causing the nodules to form. Since it is pretty much poolwide and also in the new part (spa that was added) the best solution would be a complete replaster.
Seeing as how the article that the pb is using to prove his side (that it was caused by chemical imbalance) says nothing to that effect, and in fact states that chemicals have absolutely no similar effect on random plaster spots, he really doesn’t have a leg to stand on. Oh, and by the way, that article was also written by Kim so he is very sure of the authors position on the matter.