chipmunkofdoom2
Always Making Something
View BadgesExcellence Award
Article Contributor
Reef Squad Emeritus
I think the test means chloride
Then the poster should have said that. The claim that there is 19,400 ppm of chlorine in natural seawater is factually incorrect. Chlorine does not exist in significant quantities in seawater except in its negatively charged ion chloride.
Chlorine is a powerful oxidizer and was used to kill enemy combatants in at least one World War. Chloride is an essential electrolyte in our bodies that we may not be able to live without. Speaking about these two as if they are the same makes no sense at all.
This is especially true since we are now discussing the possibility that excess chlorine in the OP's source water may be the cause of the problem. Excess chloride in seawater causes almost no problems. Excess chlorine does. This is why the distinction is important.