Retrofitting Older Toilets
If purchasing a new toilet is not possible, you can retrofit an older toilet (those that use 3.5 gallons of water per flush or more) so that it uses less water each time it flushes. You can do this in a couple of ways:
Install a Toilet Tank Displacement Bag
One way to retrofit an older toilet is to install a toilet tank displacement bag in your toilet tank. Once filled with water, the bag will displace about .5 gallons of water in your toilet tank so that your older toilet will use less water each time it is flushed. Many water suppliers give them out to their customers for free, or you can purchase one at most home improvement stores.
Install a Toilet Fill Cycle Diverter
Another way to retrofit older toilets is to install a fill cycle diverter. The fill cycle diverter is a simple plastic device that directs more water to the tank and less to the bowl while they refill so that they finish filling at roughly the same time. Once installed, a fill cycle diverter will save about .5 gallons of water with each toilet flush.
How a Toilet Fill Cycle Diverter Works
When a toilet is flushed, both the tank and the bowl need to be refilled. For many older toilets, the bowl will fill sooner than the tank. In this case, the water will continue to run into the bowl until the tank water level is high enough to shut off the fill valve. Water that enters the bowl after it is full simply overflows down the drain and it wasted.
The fill cycle diverter directs more water to the tank and less to the bowl while they refill. The goal is to have the tank and the bowl finish filling at the same time, or as close to the same time as possible.
Many water providers give them out to their customers for free, or you can purchase one at most home improvement stores or online.