krj wrote:

How many days will a 13 gallon tank last for 2 people before having pump
it out?


Here's the math you need to know about how long it will take to fill up
any size tank:

The average adult uses the toilet 5x/day...average flush is .6 gal. So
each person continuously aboard will put about 3 gal/day into the tank.

So if there are two people aboard, that's about 6 gal/day...or about 2
days before you need to find a pumpout. You'd be smart to consider the
13th gal. to be your margin of error.

Keep in mind those are averages. You MIGHT be able to stretch it another
day if you use shore facilities or the lee rail or go swimming as often
possible..and also learn how to use the "dry" mode except to rinse the
bowl (any manual toilet that's working even close to specs can move bowl
contents up to 6' in the dry mode). Otoh, your toilet may use a bit
more flush water than .5 gal. Or you may have to pee more than 5x/day.
There's just no hard and fast answer to how many flushes a tank can
hold...which is a good reason to install a gauge.

In fact, although it's rarely enforced, CG regs require some means of
determining when the tank is at least 3/4 full. If the tank is readily
accessible for visual inspection--and is translucent plastic that'll let
you see how much is in it, that's acceptable. But if it's not, the regs
require a gauge.

--
Peggie
----------
Peggie Hall
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"
http://shop.sailboatowners.com/books...ku=90&cat=1304