[midgetwaiter]

This is interesting, given the higher pH of the tap water in Calgary I would think significant heavy metal contamination is unlikely. Lots of older places, like my house for instance have copper pipes.

Aquarium Pharm makes a pretty cheap copper test kit, I'm not sure how good it is but it would be an easy way to start. Be sure to test the tank and the tap water, it's always possible that a silly guest or an accident resulted in a penny stuffed under a rock somewhere.

Chlorine is more unlikely to be the issue here. Calgary uses relatively little chlorine (no chloramine yet) and naturally being a gas it will be out of the water rater quickly. I don't treat any of my FW or FO tanks at all when I do water changes or top ups and the reef tanks only get it because of the clams and only if I haven't mixed the water overnight for some reason. It is possible for chlorine levels to be increased for a short period, bad run off from flooding for example, and that could cause problems but certainly not chronic problems for 10 years.