Multi-user personal multi/dual flush toilet conversion

If you want to save water, you really need multi-volume flush. Kids are different from adults. Boys are different from girls. Morning is different from night. And each meal is different.

Also I have a huge tank that money can't buy. It looks brand new and will last forever. The bowl do have hairline cracks inside but with my constant automatic bleaching system, you can't notice the cracks. You can see the cracks only if there are dirt or water deposits - not possible with constant bleach and crystal clear water.

They are many incentives and tricks to get you to get a new toilet. All the toilet seats now do not fit the mounting holes of older toilets. But I got a slightly flexible one that will fit!

The adjustable flapper is fairly consistent. It flushes about the same volume of water every time (except for the different level of water in the bowl due to different refill times). So this is the flush number one.

Holding the flush handle for a couple of sec more is pretty easy, and many people already have been doing it. The less water flush #1 uses, the less is the time to hold the handle for flush #2 and #3 etc.

The only thing needed is to visualize the level of water in the tank and let go of the handle at the right moment. This can be done by a vertical, calibrated, tube outside of the tank. But this is inconvenient to look at.

Electronic water level detection is easy and cost almost nothing. So there will be a bank of LED's for indicating the level in the tank, digitally. You can also use different tones or sophisticated displays. But the aim is to compete with those $20 conversion kits. LED cost at most a few dollars per pack.

You need one simplest transistor and a few resistors per level. That's cost about nothing. The circuit is trivial and I will give you one when I come round to it. Water is about a 20k resistor, the presence and absence of which is a reliable switch. Using one AAA battery, the transistor drives one LED when water is absent.

A low current design is required for the battery to last long, say, a couple of months. But it's simpler to enable the circuit only when the flush handle is turned. An AAA battery will probably last for a year or two. And a normally cutoff circuit minimize corrosion due to electrolysis.