Home>Discussions>BATHROOMS>How can I use less water per flush?
10 posts / 0 new
Last post
nancyberlo
How can I use less water per flush?

What, if anything, can I put in the toilet tank to take up space and thereby use less water per flush? I have a regular 20 yr. old toilet with the plastic insides, instead of the old ball cock thing. They used to tell us to use a brick, but I know that is a bad idea because it deteriorates over time. What are the latest thoughts on this. I know we use way too much water than is necessary during this drought.

handycauseofdad
Re: How can I use less water per flush?

Why not just put the brick in a zip-lock 1 gal. freezer bag?

Or you could put some rocks in a ziplock bag or a old pair of your wifes nylons?

Just some thoughts.

YMMV.

Kev

JLMCDANIEL
Re: How can I use less water per flush?

Fill a 1 liter plastic soft drink bottle with water and place it in the tank. Larger than a brick and won't deteriorate for a thousand years.
Jack

canuk
Re: How can I use less water per flush?

Or ...... adjust the fill valve inside the tank for less water.

JLMCDANIEL
Re: How can I use less water per flush?
canuk wrote:

Or ...... adjust the fill valve inside the tank for less water.

Won't work, for a proper flush the hight of the water column is necessary.
Jack

canuk
Re: How can I use less water per flush?

Hmmmm ... not sure I follow you Jack.

When you place a brick , pop bottle or any object in the tank it just displaces the volume inside the tank which is the same of only filling with the same amount of water.
I'm not sure what the height has to do with the flush?

JLMCDANIEL
Re: How can I use less water per flush?

The hight of the water is what gives it the pressure to flush. You can flush a toilet with ¼ the water if you narrow the tanks diameter and increase the hight. If you only fill the tank ¼ full you won't get a flush because there is no pressure behind it. That's why you are suppose to set the fill height so close to the top of the overflow tube. Pressurized toilets with pumps to build pressure can do a full flush (I forget what volume of waste material is used for the test) with as little as 9/10 gal of water.
Jack

canuk
Re: How can I use less water per flush?

Toilets are usually rated by the gallons per flush.

Doesn't the line also represent the volume of water ... for example a 5 gallon tank would be 5 gallons at the line.

So whether you displace the volume inside the tank with an object netting only 4 gallons or filling the tank with 4 gallons without an object installed is the same volume of water.
It's more about the volume of water rapidly rushing into the bowl that creates the siphon not really the pressure in standard toilets.

With the 1.6 gallon there's 1/5 the volume of water ... which by itself isn't enough to move stuff .... hence the pressure assist.

JLMCDANIEL
Re: How can I use less water per flush?

Pressure is also a factor in the design of the toilet. That's why there is a little jet tube in the bottom of the bowl. You can slowly pour 1 million gallons of water in a 3 gal flush toilet and never cause it to flush, you can also dump the tank in a toilet and not flush it if the jet tube is plugged. The hight of the water (water column pressure) determines the initial pressure of the jet. And the pressure calculation is an integral part of the design of toilets. Sorry I can't remember more specifics but it's been 40 years since I studied this in pre-engineering .
Jack

canuk
Re: How can I use less water per flush?

Jack ... I think we're getting into "Pascal's Law" territory or fluid dynamics in which one of the variables is weight of the fluid. Although the weight of water ... in this case ...... remains constant per unit volume ..... changing the volume of water changes the weight .

None of the physical dynamics of the toilet's design changed ... the channels in the bowl still allow X amount of gpm to flow. Whether you displace the volume of water with an object in the tank or fill with the same volume will result in the same gpm.

Actually by directly pouring water rapidly into the bowl it will empty .... how much and for how long will determine the evacuation of the contents.

Anyway .... didn't mean to hijack the thread. :o:)

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.