First signs of system descaling came on March 12, 1997, nearly four months after the HYDROLATOR installation. During an outage it was seen that several stabs of scale, up to one foot long had fallen off of the thickener trough walls. Three months later even larger slabs of scale were seen falling off of the sides, some up to three feet long and ½ inch thick.

Photographs (not shown here) were also taken from inside of spools of the clean and dirty water lines, beginning from the start of the project. The clean water section of pipe is 14 inches in diameter, made of fiberglass, located just as the water enters at the bottom of the scrubbers. One photo shows this spool at the beginning of the study, just before chemical addition was stopped and the magnets installed. The scale inside of the clean water line was a hard thin silty layer uniformly covering the pipe. During the March 1997 outage, the top layer of scale was observed to be peeling away. At this time, the scale could be easily scraped off with a hard object. During the May 1997 outage, it was apparent that the bottom layer of scale was starting to strip off the pipe interior. At this time, large areas of bare fiberglass were visible. By July 1998, the clean water spool was completely clear of all scale except for a thin layer of particles. The translucent fiberglass spool, was seen to be free of scale, with sunlight passing through the rolled section of pipe.

Similar evidence of descaling were found in the dirty water line. This spool was also fiberglass, with an 18-inch diameter. At the beginning of the study, a thick (over 1/2inch) scale covered the inside of this entire spool. During the outage in March 1997, the scale was beginning to soften and could be chipped off in thick layers. By May 1997, thick layers of scale had stripped away and small areas of the bare pipe could be seen. In June 1997, the bare areas seen in May were expanding and the scale was continuing to clear. By July, large patches of bare pipe were visible.