Defeating the Flushmaster patent: automatic toilet bowl cleaner

You really never have to brush the toilet bowl again for less than $1.  You only need to open the toilet tank maybe once every 6 month and drop some super cheap household chemicals in it.

My previous improved version of the Flushmaster split the water from the fill tube into 2 paths, but still using the Flushmaster.  It was a temporary fix for prove of concept.  Once the concept is proven, using the Flushmaster is totally unnecessary, overly complicated, inconvenient, and unreliable.

Since my new design is patentable, I look up the patents reluctantly.  Reluctantly because there's not much money to be made because everybody can build it for less than $1.  But still, many people will still want to just buy and drop one in the tank and forget about it.  Fortunately, Flushmaster has already patented the concepts in 2007, so I can disclose my findings immediately and not spend my time in the toilet business.

The current Flushmaster gadget is patented about 2001.  Why they don't give you products with the new 2007 patent? Money!  Now the refill cartridge sells for $7 (?) and last for about a month for a large family with older high flow toilets.  That's totally not bad if you don't have a cleaner/house keeper.  That's a steady revenue stream that the new produce will decimate.  And if you see the new thing, probably you want to copy it for less than $1.

Overflow tubes are 1" pipes slightly narrower than standard PVC 1" pipes.  So the whole thing is based on 1" pipes and fittings.  In this final assembly, the Tee on the right just slides onto the overflow tube.  Nothing is needed to modify permanently any existing fittings.

For this design, the chamber on the left stands on the tank bottom.  This is not necessary.  To secure the assembly in place all you need to do is to glue a 1" coupler to the Tee on right.  That will hold anything securely in place using the overflow tube itself.

The whole assembly need to be water tight so the chemicals don't leak a lot into the tank.   Since the assembly is not under any pressure, you can just use PVC glue to put them together without worries.

Water from the fill tube is split into two branches.  The main branch goes into the top of the Tee on right, via a 1/4" hole, drilled with a plastic drill tip so it doesn't slip during drilling.

The 2nd branch fills the chemical chamber, via a dripper or flow restricter or narrower tube or you don't even need a 1st branch.  When the chamber overflows, the cleaning solution goes into the flow tube.

Since the overflow tube and the 1" Tee is only loose fit, I put some plumber's pudding on the edge of the flow tube to seal, so chemicals can't leak into the tank.  I don't think you need it because instead of NOT allowing drop-in-tank cleaner manufacturers to destroy flippers and gaskets, the new standard seems to require everything in the tank to withstand cleaner chemicals.  I spend time for this new design because chlorine destroys drippers for gardening drip irrigation.  It only lasted for a couple of months though it is dirt cheap.

If your fill valve ever malfunctions, water goes into the overflow tube horizontally via the Tee on right.  The "critical fill level" changed a little but you can adjust it.  I think this is or can be plumbing code compliance.  A simpler gadget will be based on 3/4" pipes and fittings.  A 3/4" tube goes nicely and tightly into the overflow tube.  There is no possibility of leaks.  But the effective overflow tube size is reduced to 3/4".

1" chlorine tablets simply drops into the chamber.  But I am experimenting with something better.  Let's see this in the tank. (The old Flushmaster is there totally unused.)

Recap: standard 1/4" pipes, for fridge icemaker or gardening drip irrigation goes straight into the white fill tube.  Pick the slighter tougher ones and you can insert it far into the fill tube, forming a water tight joint.  You also need a 1/4" tee and a dripper.  I'm experimenting with the flow rate but currently I have a 2 GPH dripper.

I have an older version that uses 1" chlorine tablets.

To reduce the swimming pool smell, you can make the tank lid reasonably air tight, or you can use a standard 1" plug to cover the Tee at the chamber opening.  The dripper is inside the plug so it will not hinder the chlorine tablets when taken out with the plug.  I rotated the chamber so it is lower profile to fit into the tank with the plug half in.

Chlorine tablets can go through standard 1" pipes, tees and caps, but NOT plugs.  So you have to allow enough space if you use plugs instead of caps.

I do not recommend expensive 1/4 tee's.  It's easy to take the tubes out but only when not inside the tank for months.  Drip irrigation tee's are much cheaper.  If you ever need to disconnect the tubes, cut the tubes, discard the tee and the tubes.

To really reduce the chlorine smell, like any drain you can add a u-trap at the open tee.  It's clumsy for 1" fittings but there's should be enough space for that.  The u-trap should be refilled with fresh water every flush.  The top level of the u-trap should be slight higher than the overflow tube so water will go into it rather than the tank.

Again, there's nothing wrong with the Flushmaster, but you can be environmentally friendlier.  First, they use a lot more chemical than required.  Their new patent sort of admitting that, or, you do not need to buy expensive slow dissolving tablets to avoid refilling too often.  They design the rubber seal so flimsy that you cannot refill it yourself with chlorine tablets. You can at most reuse the o-ring a few times.  I have yet to find o-ring in hardware store to fit without using pliers to twist the cartridge out.  My design works at low pressure and you don't need any seals.

As for the new chemical, I can hint that it is very cheap and easy to find.  If your tank is larger you can fit in a few chambers and you might not need to refill in a year's time.  I have calculated the solubility of chemicals and nothing seem to last a week  unless you make some large crystals so they dissolve much slower.  But this is barking the wrong tree totally.  You'll see.

Super flush and sparkle a great success

The little hardware used almost immediately earn it's worth.  The chlorine tablets for swimming pools are much cheaper, last for weeks each, and you can even find it in Albertsons's supermarkets.  The pungent chlorine odour for the first flush in the morning is gone.  The toilet bowl remains crystal clear.  When it's not so clear you know it's time to add tablets.

The dual flush conversion doesn't work.  Its because the toilet bowl (not the tank) do not fill up full every time.  Using siphon to continuously fill the toilet bowl isn't practical.  Too risky.

The dripper did get blocked after some weeks.  But it's very cheap.  Now I'm using those that can be opened up to unblock or to see what happened.

Multi-flush toilet problems

Previously I discovered that my old 13G toilet can use as little water as new dual flush toilets, and maybe even less, because I have 2nd chances.

The adjustable flappers can reduce the water usage but maintain powerful flush. The problem is the refilling of the toilet bowl. Because less water is used, the tank refills faster, but the toilet bowl do not have enough time to refill, about an inch or less water level. This lead to very poor flush. Because of the poor flush, the toilet bowl will still be full after flush. So the next flush will be perfect. I call this odd-even flush phenomena.

You still save water if you need to flush twice for the even flush. Sadly no conventional valve can be adjusted to refill faster.

My experiment is to siphon water from the tank down the toilet bowl continuously with a driper. My estimate is that about 10 liter of water is wasted per day this way. So it is equivalent to a few flushes. So if the toilet is used a few times a day it will break even. The problem is having enough time in between flushes for the bowl to refill.

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.

Your dual-flush toilet conversion kit may not work

And here's my very cheap multi-flush system.

I think I still have the 13 L (3.4 G) flush toilet, or even larger. It's pretty easy to use inexpensive hardware to save water to 6 L or less (<1 .6="" a="" almost="" and="" br="" can="" don="" dual-flush="" easy="" flush.="" for="" g="" have="" i="" it="" lot="" man="" more="" nothing.="" per="" poor="" pretty="" s="" save="" t="" than="" think="" this="" to="" water="" you="">
If you have the post-1994 6 L low flow toilets, the first generations don't even flush well for the full volume. What can you achieve by halving the volume?

There's another complication during tank refill. The bowl is also refilled via the overflow tube (the tube in the middle of the tank). The water at the level of the bowl will depend on the volume of the last flush, which dictates the refill time and hence the refilled volume. This may not occur if your fill valve is way over refilling the bowl, or you use those kits that come with it's fill valve too.

You can do tests before deciding to convert. The motivation is that you need to empty your tank for installing anything. It can be messy depending on what is deposited and accumulated in your tank.

Before you test, you have to understand that there are at least 3 levels of flush. The least volume required is flush for pure liquid. The next I will call it paper flush, for paper plus liquid. The most volume required is solid flush. You can also add floater flush, 3-day-after flush, you know what I mean.

It happened that all my toilets have an adjustable flapper already in it, the sort with a scaled dial to vary the volume. It cost a tiny bit more than the cheapest flapper. First you adjust the fill valve to increase the volume in the tank to the maximum level, leaving a safe margin (~1 inch?) below the overflow tube. Then you test by adjusting the flapper to get the desired flush. If you do not have an adjustable flapper, you can just keep the flapper open by hand and measure the water levels at the tank.

I found out that for my old toilet, 4 to 6 L is required for all the 3 different flushes. That means you do not gain anything if you have already a low flow toilet. If you have a high efficient low flow, you may still flush a lot of things by reducing the volume.

Let me say it this way, if you add food dye at the bowl, the amount of water you need to flush depends on how much dye you use. So you can't get away with much less than 5L of water all the time. Actually for pure liquid, you don't really need to flush. You can just add water at the bowl via the overflow tube, until the food dye disappears.

If the volume is enough to flush paper, you don't need much more water to flush solids.

So, if dual-flush is pretty useless, do I need a new $500 dual-flush toilet to really save water?

No. It dawned on me people do dual-flush all the time. By holding onto the flush handle, people empty the whole tank of water into the bowl to achieve a mega flush, when the normal flush fails.

So this is my ideal of a multi-flush system for almost nothing:

Firstly, there is the tube at the top of the tank, coming up from the back of the tank. This is just to push the fill valve open with a ring of tube, through the hole at the back of the tank, and refill the bowl via the overflow tube. You stop pushing when all the color of the food dye disappears. This is a bad 3-minute implementation but someone can improve on it.

The indicator is the main component of the multi-flush system, located at the corner of the tank, just below the flush handle. This is just a 1/4 standard fridge water tube, with the other end at the bottom of the tank.

You can see two mark at the tube indicator. The top mark is the level of the full tank. The bottom mark is the level when the flapper closes by itself. Currently this is about 5L, enough to flush paper and solids most of the time.

This is the normal or number 1 flush. Before the flapper closes (before the water level drops below the bottom mark), you hold on to the handle and let the water level drop some more, until you think it's enough. So you have multiple flush levels.

Having an old powerful toilet has its advantages above those poor low flow ones. If the number 1 flush fails, I still have up to 10 L of water in the tank to complete the task immediately, instead of having to wait for the tank to refill.

If this is a guest room toilet I don't recommend it at all. Here I would recommend a single 5 to 7 L flush, and tell all the family only to use this bathroom for solids only, but don't tell the guests.

If you have small kids that don't understand much, you can have a bathroom with 3-4 L for boys only, and a bathroom for girls with 5L for liquid and paper flush. If you really need to save the planet, you have to teach them that pale yellow is OK, and residue white paper in the bowl is OK.

The indicator is just a tube that runs over the back of the tank, below the lid, to the bottom of the tank. At the moment I tape the tube to the tank with packing tape. The L-bend quick connector you see is just to avoid curving the tube too much. At the beginning, you have to siphon out the air in the tube, using your mouth or a baby ear and nose pump.

ps Don't leave the tube for long without securing the end. If the end of the tube drops down, the tank will drain and the refill valve will open forever. This lead to another better idea.

Fluidmaster Flush 'n sparkle improved

The Fluidmaster Flush 'n sparkle fits in the toilet tank. It dispense cleaning chemicals whenever it flushes. You can keep the whole toilet bowl clean without brushing.

It's an improvement over those drop-in-the-tank solid blocks. A typical one is by Clorox, a 3 inch diameter block, which dissolves slowly in the tank, and is suppose to last for a couple of months. If you are single, or a working couple leading an active lifestyle, it would probably last that long.

The only chemical you want is chlorine bleach. The acidity neutralizes the calcium deposits in water that form water stains. The problem is that for the first flush in the morning, you will be overwhelmed with chlorine, like swimming in the pool just after chlorination, and much worse.

More importantly, chlorine attacks soft plastic used for flapper parts. You need to get chemical resistance flappers, now commonly sold.

The flush 'n sparkle is an improvement. The refill block is smaller, designed to last as long as those Clorox blocks, which isn't that long. You still smell chlorine especially in the morning. By dispensing straight into the bowl, chemical attacks are eliminated.

But still the FNS dispenses too much bleach, needs refill too fast and too expensive. Here is the improvement.

The white tubes and parts are the original FNS, going from the valve and into the overflow tube. The parts added are the splitting T, and a 1 GPH dripper. To join the parts, I use standard 1/4 inch (OD) tubes, which are used for the fridge, and drip irrigation.

The tubes used in toilet tanks are 1/4 ID (internal diameter) tubes. I can't find parts for it, but standard 1/4 OD tubes fits inside it nicely, as in the picture.

The splitter ensures that there are enough water going into the toilet bowl, independent on how much water coming out from the dripper. Here I use quick connect, or John Guest, which is under $3. The alternative is to use much cheaper T's used in drip irrigation. But those T's restricts the flow somewhat, reducing the level of water in the toilet.

The dripper ensures that bleach is dispensed in drops. Don't use those flag drippers that can be opened and cleaned. They may leak.

Using rubber bands, I tied the tube from the dripper to the original clip of the FNS. In theory, both refill tubes should be above the overflow tube, so water from the tank is impossible to contaminate via the inlet valve.

Drinking tubes for the fridge would probably work but you really need is a tough 1/4 OD tube to insert into the white tubes with 1/4 ID, and into the splitter. It also need to be elastic enough to hold the dripper well. The quality of drip irrigation tupes vary so you need to pick a good one.

The whole thing can be installed in a minute.

Also, the setup was designed to use much cheaper 1 inch diameter chlorine blocks for swimming pools. I will be saving money if each small block last for a few days. And I would like to add blocks say every week or longer.

Here is the improved Flush drip 'n sparkle in action:

Homemade Automatic toilet bowl cleaner

 For the many updates, check label "toilet"

I'm talking about:

Kaboom Scrub Free!
Fluidmaster Flush 'N Sparkle

I stumbled upon the earliest form of toilet tank mounted cleaner on the net many years ago. The idea is so good that I brought it. It looked a little more complicated as there seemed to be a miniature valves into and out of the cleaning tablet housing. I was let to believe that the valves were the important part, controlling the correct dosage of the chemical.

Everything was good except that the chemical didn't last. I thought I had the idea of waiting for one of the giants to enter the market and they can produce some decent chemicals. I actually asked the website about plumbing code, whether it's safe without the possibility of back flow. I think the toilet valve itself guarantees that. The website soon disappeared and I thought it folded.

I think Kaboom is the next to pick up the idea. It was well made and the hardware was free too. I think I still have the early version called No Scrub somewhere under the sink. It used crystals and was still dissolving too fast. I don't think it last 3 months. The housing is a bit big and I thought of putting something else in it too but if I never thought I can come up with something better than them. The lid is screwed on and it's a bit hard to open it to refill.

Than came the Fluidmaster Flush 'N Sparkle. It's more professional. It's compact. The cartridge is easier to pull out and replace, because there's an O ring to seal the housing, requiring less effort than just a screw cap. The major advantage is that it's available in hardware stores together with other Fluidmaster hardware. Again it doesn't seem to last 3 months or 1000 flushes, but long enough.

Yes, all the stuff works well. You don't really need to scrub. Try the Clorox tablets, 3" white bleaching blocks in supermarkets and everywhere. You drop the thing into the tank and that's it. The problem is that you can't control the dose. In the morning the first flush is concentrated chlorinated water. It's worse if your toilet has no windows, relying on extraction fans for the ventilation. The other problem is that chlorine attacks the soft rubber flapper of the flush valve. I think you have to replace them, say, every year or two. Consequently there are chlorine/ chemical resistance versions in the hardware stores. It's trivial to replace the flappers, but it cost a few dollars, and otherwise those things never break.

The only thing you need is chlorine tablets like Clorox. It's simple chemistry. Hard water contains mineral which are calcium minerals, or from natural lime stones. To dissolve them you need acid, and chlorine react with water to form hydrochloric acid. I hate corporations trying to sell bacteria killing stuff to ignorance housewives. Bacteria cannot survive without water and air. And if chemicals can kill bacteria they can also kill you in sufficient amounts. This time chlorine tablets are over kill for killing bacteria. In this case, you really don't need to kill bacteria in the toilet. There's plenty of them and they don't come back. Bye. The bad thing is that they will kill the good bacteria in the septic system.

Other cleaners without bleach are just like detergents, surface agents preventing dirt from sticking on the surface of the toilet bowl. They don't work that well against lime and definitely not on lime filled toilets. With chlorine tablets old toilets will become sparkling white with time, if the surfaces aren't damaged by scrubbing. The other acid cleaner are CLR, now with an organic acid form. It's as good as any toilet bowl cleaners. But I can't find any slowing dissolving acid in tablet form.

As for environmental impact, chlorine isn't that harmful. A small amount isn't toxic as it's used in most swimming pools and in the water. Chlorine will eventually form natural occurring stable mineral salts, which is totally harmless. As long as you can use as little as possible, you don't waste resources to produce it and minimize changing the acidity of the discharge environment.

The Fluidmaster is good but I have 3 toilets. I have to replace them all in one to two months. Sometimes I was too lazy to do it and it cost about $8 each? Using a brush and a liquid bleach every few months isn't a big deal, until one toilet turned black at one of the surface cracks. Well, the option is to replace the toilet that isn't necessary and too big a deal if I were to do it myself. If you keep it sparkling white you can't see the cracks.

The story goes: one day I found an old Clorox tablet 3" in diameter. I found out that the Fluidmaster cartridge can be opened to refill. So I crushed the tablet into smaller pieces and put them back in the cartridge.

I searched the net and if you have a swimming pool, you know what I was thinking. I found those 1" diameter chlorine blocks for swimming pools. Buy many swimming pool owners have thought of it and tried it. One plumber guy used it and do not recommend it mainly because the tablets are of different dissolving rates and the swimming pool is a lot of water compared to the toilet tank. But he was dropping the blocks into the tank like the Clorox ones.

I think those swimming pool chlorine tablets will work well. Firstly they are slow dissolving. They are much cheaper than those for toilets. The 1" ones fit right into the Fluidmaster cartridge that I measured. If these tablets dissolve too fast and you loose money compared to using the original cartridges, you can leave some time gaps between replacing the tablets. Acid is rather good in dissolving old calcium deposits. You just need to replace the tablets before deposits become visible, or just become visible.

Further down the road I don't think you even need the dispenser. It's pretty cheap to make one perhaps. If not you can just make one to show off. Parts:

1.5" diameter PVC tube (enough to accept 1" tablets)
John guest adapters on both ends, or tube adapters
two sort tubes

The tube used in the toilet valve seems to be not the standard 1/4" tubes, but at least they are standard. You must be able to find it in the hardware stores or cut the original piece into two. The installation becomes inserting the outlet tube into the central tube of the tank, securing using fancy clamps or just rubber bands. You can mount the whole thing at the side of the tank of just drop the sealed tube into the water.

You can have a fancy union to make it easy to open the tube and refill tablets. Really there are plenty of space in the tank to do some awesome stuff.