Creating access hole in fresh water tank.
I tried the hose method and found it quite messy...I'm a clutz...so I (gained access) cut a hole in the top of my fresh water holding tank. 1 1/2 inch hole saw. Sever the neck of any plastic bottle. Find your handy tube of Goop and have at it. One cup of bleach per 55 gallons of water for killing unfriendly bacteria in tank and lines. Flush well!
"If everything seems to be going well, look around, you've obviously overlooked something."