How VacuFlush^® Improves Holding Tank Efficiency

“How many flushes will my holding tank hold?”

That’s a typical question many boat owners ask about their holding tank. The answer depends on what type of toilet is being used.

A manual or electric toilet can use one gallon (3.785 l) per flush. If you have one of these toilets, the total amount of effluent (water and waste) per flush would total 1.14 gallons (4.31 l).

A VacuFlush toilet, on average, will use only 0.2 gallons (.76 l) of water per flush.* This brings the total effluent per flush to 0.34 gallons (1.29 l).

Based on this information, you can easily calculate how many flushes a holding tank will hold. The following examples reflect the capacity for a 20-gallon (75.7 l) holding tank:

“How many days will my holding tank last?”

When planning a trip for a number of people, you can now calculate how many days you can travel between pump-outs. Based on a trip with four adults, here’s how long a 20-gallon tank will last:

As you can see, a VacuFlush toilet can greatly extend the use of a holding tank between pump-outs as compared to manual and electric toilets.

* VacuFlush toilets use as little as 0.13 gallons of water per flush. Because we recommend adding more water when flushing solids, we conservatively estimate average water use at 0.2 gallons per flush.

Efficiency Comparison Chart

Water consumption per flush can vary due to different water pump flow ratings.