Sometimes PR-10,000 can discolor the water when it is added to a pool with dissolved metals, Here's why.
If the water turns green or brown, it's from metals being oxidized and discoloring the water. Brown/red discoloration is likely iron, green/turquoise is likely copper.
If metals are already in the water, why does PR-10,000 make them show?
Normally when this happens, there is a phosphate-based sequestering agent in the water. PR-10,000 wipes out the sequestering agent, the metals go free, and chlorine in the water oxidizes them.
Without a phosphate-based sequestering agent in the water, discoloration from PR-10,000 is unlikely. If anything, the discoloration would come from chlorine, not PR-10,000.
Are there any metals in PR-10,000?
PR-10,000 is an emulsified rare earth mineral, so technically, yes it contains metal. But it does not contain heavy metals that discolor water, like iron, copper, or manganese.