I drain the pink stuff out completely, put a couple of gallons of water in the tank and then pump it through all the faucets. Then, I do like Ron. I put a couple of cups of bleach in the tank and then fill it up to the rim with the hose turned on full to force as much water as fast as possible down into the tank to agitate the bleach and water together. Then, I pump some of this solution through every faucet, shut off the pump and leave the bleach solution in there overnight or sometimes even a little longer. Then, I drain it out completely with the three drain valves. Then, refill with fresh water and off I am done.
Unlike Tom, I open the hot water heater bypass valve and fill that tank also with the bleach solution. By the way, when bypassed and winterized, I leave the drain plug in the tank out of the tank all winter. Also, I use a wand made for the purpose to thoroughly wash out the tank prior to refilling in the spring. Now, with the PC aluminum tanks that don't have an anode like the older tanks this is not so much necessary. In my other rigs over the years, I left the anode out all winter and I rinsed it at the end and beginning of the camping season with the wand sprayer.
I will add further that we do not drink water out of the PC system. We buy and carry bottled water replenishing it as we use it. Just got into that habit over thirty years ago and that is we do. Some of the places we go the water may or may not be to peachy and we figure why take a chance for less than a buck a gallon for generic water from the grocery store.
Pau l
