The phrase “water saving toilets” or low flow toilets refers to toilets that use 1.6 gallons per flush (GPF) or less.  It may be that you remember, or still have, a toilet that gorged itself on water.  Some of the older toilet models used 3.5, 5, or even 7 GPF.  To cut back on the amount of fresh water that was being consumed, the Federal Government passed a mandate that required all plumbing manufactures to make their toilets meet a more stringent standard.  This mandate took effect in 1992.  The new standard for toilets was that they had to be 1.6 GPF or less.

Early models of low flow toilets had various difficulties as manufactures tried to perfect their designs. Often, a common complaint from consumers is that their water saving toilet does not flush as well as their older gallon guzzler. While this is true of some makes and models, it is not true of many well designed modern toilets. Here is a list of common types or water saving toilets: gravity-assisted toilet, dual-flush gravity-assisted toilet, pressure-assisted toilet, and vacuum-assisted toilet. Let’s discuss some of the strengths and weak points of these low flow toilets.

The most common and the least expensive of these toilets is the gravity-assisted toilet.  This toilet has a basic design inside the toilet tank that most of us are familiar with.  It has a simple flapper valve that when pushed opens and allows water to flow out of the tank, by gravity, into the bowl flushing away wastes.  This kind of toilet’s strengths are that is relatively inexpensive and low maintenance.  The weakness of this style of toilet is that its flush is the weakest of the four types.  Still, there are several models that despite a weaker flush work very well.  Additionally, Some models are designed with an extra big toilet trap and flapper opening.  These larger orifices present little resistance to water flow and thus allow less water to flush the toilet more effectively.  Typically, these toilets cost a little more than the standard models but they work very well.

Dual-flush gravity-assisted toilets offer two ways to save water.  They are designed with two flush options.  One option is for a flush that provides the full 1.6 gallons to remove solid waste.  The second option is for a half flush (.8 gallons) to get rid of liquid waste.  The strength of this toilet is that it works well and conservers water efficiently.  It chief weakness is its price. It is one of the most expensive styles of low consumption toilet available.

Next consider the pressure-assisted toilet.  This toilet uses the pressure from the water feeding into you toilet tank to compress air that is captured in an airtight container inside the toilet tank.  The water continues to flow into this container until the water pressure equalizes with the compressed air pressure.  When the toilet is flushed the pressurized air pushes the water, adding its force to the falling water.  The strength of this kind of toilet is that it does flush very well.  However, this toilet style has a few weaknesses.  One weakness is that they tend to be noisy when flushed.  Another weakness is that they often need more repair work than other toilets.  Lastly, these toilets tend to be expensive.

One final toilet style to consider is the vacuum-assisted toilet.  When you flush this toilet, a vacuum chamber is started creating a siphon-like effect to help draw water into the toilet bowl.  This method of flushing helps the water to clean more of the surface area in the bowl.  This toilet is quieter than a pressure-assisted toilet.  So the strengths of this kind of toilet are its cleaner and quieter flush. Still its weakness is that its flush is less powerful than a pressure-assisted toilet.

Now that you are armed with more technical information on the strengths and weaknesses of water saving toilets, you should be better able to make an informed selection that will benefit the environment and your preferences.