How do you change a 1.6 gpf toilet to be a 2.5 gpf toilet?

If you have a Gerber toilet you can buy a replacement flapper at your local hardware store. Gerber uses a weighted flapper and if you use an aftermarket one you can have the flapper stay open longer so more of the water empties into the bowel. You can't really raise the level in the bowel. If you have a Kohler you can shorten the distance from the flapper to the foam float and this will do the same thing. You do this by taking off the 2 plastic clips. 1 on the top of the foam and 1 on the bottom. Put the lower 1 right on top of the flapper and put the other on top of the foam after you push it down tight against the bottom 1.

The GPF is directly related to the total amount of water that you allow into the bowl, the tank outlet size and the water outlet size.

To convert most any toilet you need to switch out the top tank. This will give you a larger volume of water. You will probably need to visit several wrecker yards that deal in older home demolition. Make sure that the tank matches the bowl. You could also consider converting it to a literal water closet where the tank is suspended above the bowl about 4' and attached with a down pipe.

The change in bowl size does not mean you will get the increased flush rate, but you will get a longer flow time which will help move the fecal matter to the appropriate outlet area.

God Bless

you wont make the water level in the toilet bowl change. it is built into it. inside the back there is a sort of trap. when the water level comes up to this trap, it will stop. if you added more water, it would just flow over the trap and still be the same heighth. maybe another toilet. i assume you are talking about the water left in the bowl when no one is using. if so, i am correct, and changing the amount of water in the holding tank will not help you at all.

Gerber 1.6gpf Toilet

I think you can get a 3.5 gpf toilet from canada. Check Ebay out. Say by by to #2!!

previous answer was somewhat correct, however if u spend the xtra bucks and get a kohler elongated bowl, can be two piece tank and bowl, your problem should flush away, not cheap, @ $500. parts alone, but as a life long plumber, i have one at home and never have a# 2 problem

There is no adjustment only replacement. If you live in California watch out for the water police.