# Worthwhile invention?

I don’t plan to fool with it myself so not worried about somebody stealing my idea. Anyway a lady with a small restaurant was trying to track down the source of a water leak. Her water bill has been going up but business in not up. The only suspicious thing I saw was one of the toilets was a couple of inches below the fill level and when I came back and rechecked 1/2 hour later it was full. So I assume the tank leaks down and then refills because of the leak.

I thought if a person could come up with a monitor that could be installed in the back of a toilet that would not detect flushes but detect slow drops of the tank level and then somehow register them it might be useful in detecting slow leaks that are not obvious. Water is really expensive here and if you go over your limit they charge you a sizable penalty. I figured out a design that would ignore the flushes but have no idea how to make it register and count the refills.

Right now there are kits replacing the innards of the tank which are deliberately noisy. So when there is a slow leak, and the tank refills, it is very noticeable. Your invention would compete with this.

here’s my design:
Two pressure gauges, one at the top of the tank,one half way down.They are electronically connected to each other.

When the tank is full,there is a certain quantity (and thus pressure) of water at each gauge. This pressure remains constant and unchanging.
When the tank empties for a flush, at each gauge the pressure changes to zero, from the regular, constant and known pressure.
This change happens at both gauges as they suddenly (within 5 seconds) register zero.

The electronics are programmed to ignore readings of zero which happen within 5 seconds, and then return to normal pressure within 30 seconds.(i.e. a regular flush)
If any other changes in pressure occur, a red light blinks.

So if the tank has a small leak, as the water level drops a half inch, the pressure gauge at the top (say, a half-inch below the water level) will become zero when it is no longer under water.But the lower gauge will barely change. So the red light starts to blink “check toilet”.

Of course, most people will ignore the "check toilet"light, just like they ignore the “check engine” light in their car.

Turn the water off to the toilets at night. Check the tanks in the morning to see if they have gone down. Those would be the ones with leaks.

I doubt that the pressure gauge solution would work, but you might be able to do this with a microphone.

I believe this already exists. Check around.

I think this concept could work pretty well. The pressure difference might be an issue but a float attached could easily accomplish that.

You’d just need one switch at the bottom to read the pressure of the water column above it. Set the indicator to show when the pressure is less than whatever level. Typically switch have built in differentials to stop chatter. For that matter you can put some type of acustic or capacitive sensor right above the full water level that trips when the water level gets out of range. This whole thread is trying to duplicate a float switch.

ETA a differential pressure switch with one probe at trip level and the other in the tank should work also.

I don’t think what you propose is patentable. You are proposing using ordinary components and materials to solve a problem, and in your proposal there’s nothing surprising.

If unnoticed toilet cycling was a known problem, a “long felt need”, and numerous attempts to solve this didn’t satisfactorily address the need, and you had some novel idea that brought about the solution others had not turned up, then you’d have something. For example, if it turned out that storing your bathtub rubber duckies in a basket that hung off the flush handle had the surprising unanticipated effect of fixing this problem, that would be patentable by whoever filed first (or actually whoever started documented work on it first that lead continuously up to a filing).

I’m not a lawyer. I have 7 patents and took one course in patent law aimed at inventors.

Actually, the Patent Reform Act of 2011 changed the law so that the patent goes to the first inventor to file. It is no longer based on who invented it first. You have to have invented it, but then it is a race to the patent office.

I have no personal interest in it. I was just suggesting their might be some need for such a device. Simply checking the water level for a couple days in increasing time intervals would tell you the same thing and is how i would normally do it. But going to a business or residence with several toilets and a customer who is not interested in finding his own leak it might be handy. The plumber could simply come back the next day to retrieve his gauges and see how they reported.

We’re over-engineering this, but it’s fun. How about a float connected magnetically to the wiper of a sealed linear potentiometer, that’s mounted vertically in the tank, and is connected to an Arduino or the like, that uploads the voltage level every x seconds (configurable setting), to a cloud server that you can access from your smartphone, where you can view graphs of the water level for the past hour, day, week, etc. Sudden big dips in the graph are obviously flushes; more gradual, smaller, less-steep drops followed by small sudden jumps (refills) are obviously leaks. Plus you can tell in real-time who flushes and who doesn’t.

Build an entire social network around it called Dumpr? Flushr? Encourage people to share photos of their epic dumps. (You think I’m crazy? We were already halfway there with the “girl selfie on the toilet” Facebook photo craze of a few years ago.) Your turd photos are rated by your friends and you earn karma points, except they’re called “polish.” “You have 9,873 polish on your turds!”

You’re welcome.

I could mechanize this with two brass (or even plastic) rods, two weighted floats and two plastic tally-counters.
Hang the rods on the inside of the tank.

Calculate the pressure required to depress the button of a tally-counter.
Set one tally-counter at the bottom of the tank at the base of a rod.
Put the other tally-counter on the other rod, with the button at the level where the float valve is set to stop refilling the tank.
Set the floats on the rods and weight them an ounce or two heavier than minimally needed to allow gravity to apply the force required to push a tally-counter button.

Calculate the volume of water required to raise the float on the float valve from the start filling to the stop filling position. Let’s call that a fill volume.

When water volume is reduced in the tank, gravity will cause the floats to descend along their respective rods.
When a weighted float descends far enough, it will increment the tally on the counter. The lower counter is only counting flushes; the upper one will count all volume drops.
As the tank is filled back up, the float will rise, letting the button reset to count the next tally.
Set the equipment in place for…oh, I dunno…Friday through Monday would capture weekday and weekend traffic; Midnight Sunday through 11:59 Saturday would probably be more accurate.
Volume drop # minus flush # equals number of leaks.
Fill volume multiplied by leaks equals volume of water lost during the time period. Multiply somehow to get a month’s water wastage
Multiply water wastage by water rate to figure out how much money is going down the drain each month.

An easier, time-tested method:
If a leaky toilet is dripping onto the floor it would be easy to notice and fix.
If it’s leaking into the lower section of the toilet, the extra water will eventuallly just overflow down the toilet-drain.
At closing time, drop blue or red food coloring into the tank(s). [Don’t use yellow, for obvious reasons.]
Before opening for business, check the bowl(s) – and flush so you don’t freak-out the patrons.
If water leaks from the tank to the bowl, the food coloring will change the color of the water in the bowl.
It doesn’t matter how much water is being wasted; any tank that’s leaking should be repaired.

BTW: If your friend is in a food industry, food coloring can be considered a business expense (i.e. a non-taxable purchase).
–G!