Originally Posted by Ohio-Ed
Hopefully someone will chime in that knows the answer.
I'm interested in how it would be different than what we are doing with water heater elements in our HLTs?
According to the people who installed my water conditioning system the hot water from the water heater might have a number of problems.
1. Excess aluminum or magnesium from the anode. If your water is reactive in any way it will contain minerals from the anode that were dissolved by electrolysis to prevent corrosion of the tank and fittings.
2. Hot water tanks quite often have sulfur reducing bacteria as it is a good environment for them.
3. Most minerals concentrate near the bottom of the water heater, changing the entire mineral balance. This may be good or bad, depending upon what beer you are making.
As a test, pour a glass of water from the cold tap, one from the hot tap and one from the drain on the hot water tank. Cover them and let stand a couple of hours. Look for dissolved gas coming out of suspension. Then taste compare the three samples. Make up your own mind as to which samples are acceptable to you for brewing. Personally I can taste quite a difference and choose to use only cold water in my brewing.