Originally Posted by chef2sail
I know you flush you lines super well.
If the hose which is looped with the large place for waste to get stopped in is after he holding tank,, consider what I did. I placed a 11/2 inch bronze ball valve at the exit of the tank to th waste hose which led to mu "Y" vave to either mascerator or deck pump out. The valve renaibs closed unless I am pumping or dumping thus no waste lays in t hose to stink
I absolutely do and the line in question is the line from the head in our stateroom to the holding tank, so I know its always flushed properly. Probably the longest line as well. Regardless of how much clean water we flush, a dip in the line is always going to have fluid sitting there partially contaminated. Unfortunately, you can't get at any of these lines, nor the tank, with the floor and settee installed. There are a couple of inspection hatches at best.
The problem, as I can now see it with everything removed, is how long the waste line is and where it routes. While the line must be 15 feet long, it runs 6 or 8 feet across a space with no support. The weight of the fluid must cause it to dip and over 8 years, its stays that way. I may consider coupling in an ABS pipe for just this part of the run, or come up with a bracket of some kind.