This is the recurring question homeowners ask about their storage tank. The answer: it depends on the type of toilet being used. First of all, it is worth knowing the amount of waste that an adult produces.

Field experience teaches us that, on average, an adult generates a total of 2.6 liters of waste per day, and flushes the toilet about five times a day.

This means that an adult generates 0.53 liters of waste for each flush of the toilet.

Next, we will have to add the amount of water used in each rinse to the amount of residue per rinse. This is where the type of toilet used is of all importance.

A Manual or electric toilet can use up to 3.8 liters of water in each flush. If your boat is equipped with these toilets, the total amount of effluent in each flush would add up to 4.3 liters.

A Sealand VacuFlush® toilet will, on average, use just 0.76 liters of water per flush*. This reduces the total effluent in each rinse to 1.29 liters. Based on this information, we will easily calculate the number of rinses that a given storage tank will be able to withstand.

VacuFlush® toilets are capable of operating with as little as 0.49 liters of water per flush. Since we recommend using more water when rinsing solids, we have kept this average value of water consumption, 0.76 liter for each rinse.

Manual/Electric Toilet: 17 rinses per tank

VacuFlush toilet: 58 rinses per tank

How many days can my Storage Tank last?

When planning a cruise for a group of passengers, you can now calculate the number of sailing days between two tank pumps. Under cruising conditions with four adults on board, the duration of a tank with a capacity of 75.7 liters is detailed below:

Manual/Electric Toilet (Total rinses/day x 20) : 0.9 days

VacuFlush toilet (Total rinses/day x 20) : 2.9 days

The numbers prove it: a VacuFlush toilet can greatly increase the interval between tank pumps, compared to other manual and electric toilet systems.