filters, left inline, trap bio material which then decomposes. filters are
Perti dishes to a water system, or so I was told by a guy who spent his career
designing filtration systems of various kinds.

He said the best system is to filter the water you need for the next short
period of time and then store the filter dry until the next time.

After rinsing the residual antifreeze out of my sailboat fresh water system
extensively, I filled the (~100 gallon stainless) tanks through a simple
carbon filter. Only a few weeks later, the water coming out the galley and
head sinks, cold or hot, has a definite sulfur odor. What are the best
treatments for fresh water system "purification"? Are they all
one-time-through-and rise-out approaches, or are there safe, non-toxic
things that can be left in the water as well?