Fresh Water System Sanitation Questions

[Lsuee309]

I'm reading through the manual for the RV, and it's either missing a step for sanitization or they've changed the approach based on my research. The instructions are as follows:

-Prepare a solution of 1 gallon of water with 1/4 cup of bleach per 15 gallons of holding tank capacity.
Step 1: Pour the solution into the gravity inlet
Step 2: Turn on the water pump
Step 3: Open all faucet fixtures
Step 4: Allow the solution to stand for 3 hours, then drain and flush the system

Questions:
1) Everything I've seen says to fill the tank up after adding the solution, but these steps do not have that. Is a step missing or is this related to Question 2 below (see that question)?
2) Everything I've seen says to let the solution stand for far longer than 3 hrs (8+), but these steps say 3 hrs. Is this too short of a time, or is this 3 hrs because the water has a higher bleach concentration due to not filling the tank?
3) If I'm really not supposed to fill the tank completely, should I not be worried about potential bacteria in the remaining area of the tank that doesn't get exposed to the solution?
4) For obvious reason, I'm supposed to bypass the water heater. What do people do to sanitize the heater's reservoir?

Thanks in advance for any assistance!

[finz04]

I fill the tank to full and run water through all the lines. 3 hours is plenty. I do not sanitize my WH, but I do empty it if my fifth wheel will sit idle more than two weeks between trips. I also flush it when I empty it with the probe attachment for the hose that fits up inside the WH. Not saying that is the only way, just the way I have done it over the years.