Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
I use tap water for my fish, from both hot and cold taps. My plumbing was redone about 20 years ago, converting from galvanized to copper. Hot water tank is probably about 5 years old. Prior tank was about 15 years old when it died, I think. I have been keeping fish through 2 water tanks. When I use hot water I usually let the tap run until the water is hot and a consistent temperature, then turn on the cold until the temp is just right. So that flushes out whatever water was standing in the pipes.
Depends on how old your house it, what the pipes are made of, and how old the hot water tank is.
Newer installations are probably copper or could be pvc. The water companies usually add stuff to keep the pH of the water on the alkaline side of neutral because acidic water erodes the pipes faster.
I have no idea if the hot water tank, or running hot water through the house plumbing will add significant amounts of copper to the water when you are keeping such delicate livestock as shrimp.
If you know your pipes are copper you could add a copper removing product to a small filter then run it for a while before using the water. Something like Cuprisorb. When you are done with that, remove it and THEN add dechlor, chelator and whatever minerals your shrimp want.
Alternate idea: If you already know the cold water is safe, then heat some water on the stove in a stainless steel pan. If you heat this water near boiling and blend it with cold tap water you might need to heat about 25% of the water.