I dunno what you consider expensive, but IMO $300 for a system that
can monitor the level in up to 8 tanks--fuel, water AND waste--is a
bargain. Just about every houseboat mfr now installs a version of
this system as standard OEM equipment:
http://ferriellosales.com/default.php A LOT less expensive than
other comparable systems, and also the most durable reliable.
Thanks for ordering and recommending my book...the two of you have
made me a whole $4 richer!
Peggie Hall, Moderator
Specializing in marine sanitation since 1987, Author: "Get Rid of Boat Odors--A Guide to Marine Sanitation Systems and Other Sources of Aggravation and Odor."