Randy Holmes-Farley
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My Tank Thread
The use of tap water (or not) is one of the worst cases for judging based on whether other people are successful because tap water varies so much, even from your next door neighbor. Your own pipes are typically the biggest source of lead and copper, so even if your neighbor does it OK does not mean you can.
We know from very extensive required testing of tap water supplies that some percentage of homes have way too much copper for a reef, while most do not.
Suppose that 2% (1%, 5%, 10%?) of the homes in your water district have 1 ppm (500 ppb? 100 ppb?) copper in the water. Do you want to be among the 2% which then have a problem, or do you want to roll the dice and hope you are among the 98%?
Each user has to decide based on their own risk tolerance.
This has more, including actual data:
Aquarium Chemistry: Tap Water in Reef Aquaria ? Advanced Aquarist | Aquarist Magazine and Blog
http://www.advancedaquarist.com/issues/jan2004/chem.htm
We know from very extensive required testing of tap water supplies that some percentage of homes have way too much copper for a reef, while most do not.
Suppose that 2% (1%, 5%, 10%?) of the homes in your water district have 1 ppm (500 ppb? 100 ppb?) copper in the water. Do you want to be among the 2% which then have a problem, or do you want to roll the dice and hope you are among the 98%?
Each user has to decide based on their own risk tolerance.

This has more, including actual data:
Aquarium Chemistry: Tap Water in Reef Aquaria ? Advanced Aquarist | Aquarist Magazine and Blog
http://www.advancedaquarist.com/issues/jan2004/chem.htm

