You need to heat the water to the same temperature as the tank. Check to see if your water company uses chlorine or chlorimides to treat the water. You may still need to use a water treatment to remove those chemicals. most use prime or safe from seachem. also, there may be micro-bubbles from CO2, if it is added by the company. we will need to out-gas this from your water barrel before placing it into the tank. using an air stone will help with this. most age their water for 24 hours before it is added to their tanks.