[tglass]

I believe Jpendejo's question was for the gray water tank not the fresh water system. On my 41 Open I simply take the half cover off the gray water tank, pour in a little Simple Green and scrub it out with a rag. Then flush the tank out by running it through a few cycles with fresh water. I assume the 35 Express has the same set up on the gray water tank where you can remove half of the cover. One note, prior to cleaning the gray water tank I also clean out the shower sump making sure the pump impellor is clean from any debris as well. Good luck.