Chlorine/chloramine testing and safe levels

[jcrabbit]

What is a safe level of chlorine/chloramine for an aquarium tank? I've seen the internet claiming a danger threshold at 0.1, 0.05, 0.005, and 0.001 ppm.

The main issue is that there are not many test kits available that can measure chlorine levels with a precision of less than 0.1 ppm. This makes it difficult to accurately determine the chlorine levels in an aquarium tank. Say the safe level is 0.05 ppm. In my area, the water coming out of the tap has a chlorine level of 0.2 ppm. It would be very difficult to detect trace amounts of chlorine in water that has been diluted 40 times, even with a highly precise test kit. 

Given the lack of reliable data on this issue, it seems impractical to demand such low levels of chlorine/chloramine in an aquarium tank. It seems to me, for most aquarists, it may be more realistic to simply use a chlorinator whenever using tap water to ensure that the water is safe for their tanks.

[Mmiller2001]

Zero ppm. Just dose a dechlorinator and it's no problem.