>>> "release trapped gases from the water."
The water in the domestic supply is under pressure and as such, can hold more disolved gas than atmospheric pressure water. It is always a good idea, (if using tapwater), to let it "rest" for a while to allow these gases to come out of solution.
>>> what effect copper has on fish
Most fish can take a small amount of Cu, however the majority of inverts have almost zero tolerance to copper, that is why tapwater is often regarded as useless for reef tank owners.
Something to remember is that in most hot water systems, there is a limescale coating built up on the inside of the pipes/tanks/whatever.
The water in the domestic supply is under pressure and as such, can hold more disolved gas than atmospheric pressure water. It is always a good idea, (if using tapwater), to let it "rest" for a while to allow these gases to come out of solution.
>>> what effect copper has on fish
Most fish can take a small amount of Cu, however the majority of inverts have almost zero tolerance to copper, that is why tapwater is often regarded as useless for reef tank owners.
Something to remember is that in most hot water systems, there is a limescale coating built up on the inside of the pipes/tanks/whatever.
