...getting it out of the house...

There is no single best way of doing this. The "best" way will depend on your bathroom layout and its height relative to the garden. In particular, it will depend on whether you can or want to install a thru-wall fitting or a thru-ceiling fitting (Fig. 2a - 2d on the Details page) and the type of pump you choose to use - in-line pump, sump pump, or no pump (gravity feed).

Note re pumps: Be aware that some pumps are only rated to handle water up to 35 degrees C, and a really hot shower is around 43C at the point it comes out of the shower head. Assuming that you pump the water out of the Big Bucket after you finish showering, the cold water that falls into the bucket at the start of the shower might reduce the water temperature enough, or you might need to let the water cool a bit more before pumping it out. The in-line pump I'm using is rated for 40C, so the bit of cold water before the shower runs hot reduces the water temperature enough for my pump.

In-line pump setup... 
This is what I use with my Big Bucket. For details of my pump, see Fig. 7 and the specifications on the Details page.

My setup has evolved over time, making it progressively easier to use. When I first set up my Big Bucket, a couple of years ago, it was like this:

My earliest Big Bucket configuration

I cut an outlet hole low on the side of my Big Bucket, inserted a tap, and ran a hose from the tap to the pump inlet. I placed a filter inside the bucket over the outlet, as shown in Fig. 1 on the Details page. The pump-to-garden hose that clicks onto the pump outlet was kept outside. After a shower, I would open a nearby outside door, bring in the hose and click it onto the pump. The green tap you see in the pump-to-garden hose was closed when not connected to the pump to prevent back-flow of old water. Once connected, I would open this tap and the tap on the bucket, wait a moment for the pump to prime, then switch on the pump. After pumping, I would switch off the pump and then immediately turn off the tap that prevented back-flow, then the other tap, and disconnect the pump-to-garden hose and take it back outside.

Since the bucket outlet was in the side of the bucket, I had to be there to tilt the bucket once the water level in the bucket was down to about 3cm so that it could continue to be pumped out. This would be less of an issue with a narrower bucket, but since my Big Bucket is so wide, that amount of water is quite heavy and tilting the bucket was a bit awkward. A litre or so of water would still remain, so I needed to unscrew the bucket-to-pump hose from the pump inlet and up-end the bucket to tip the remaining water down the drain in the shower alcove.

The above setup worked well, and was fairly easy to deal with - certainly much easier than carrying out dripping buckets of water by hand! However, after a couple of summers the need to hold the bucket in a tilted position and bringing in and taking out the pump-to-garden hose was starting to get old.

I decided to eliminate the need to tilt the bucket by changing the outlet from the side of the bucket to the bottom, as shown here:

My second Big Bucket configuration

The pump can now draw out all the water without any tilting - much easier! I used eco-blocks coated with silicon to raise the bucket 9cm to accommodate the outlet fitting and hose. The outlet in the bottom of the bucket has a T-fitting under it: the outlet hose with in-line tap going to the inlet side of the pump is off one side of the T-fitting, and the other side has a by-pass tap that can be opened (for example, if the garden does not need watering that day) to let the water in the bucket run directly down the drain in the shower alcove floor.The silvery blob sitting in the bucket to the left of the outlet is a pot scourer. Normally it sits in the outlet hole - its just the right size to filter hairs from the water so they don't upset the pump. The pump-to-garden hose is the same as in the earliest Big Bucket configuration. See Fig. 3 to 6 on the Details page for details of this setup.

With this second configuration, the procedure for pumping the water out after a shower is much easier because no tilting is required to empty the bucket, and the bucket-to-pump hose can stay connected all the time. A very small amount of water flows back to the bucket from the pump in the few seconds between switching off the pump and turning off the tap that prevents back-flow. However, this can be drained out very easily by opening the by-pass tap under the bucket.

I really wished I could use a thru-wall fitting to eliminate the need to bring the pump-to-garden hose in from outside and reconnect it each time I had a shower. However, my shower alcove is not on an outside wall, and the one outside wall of my bathroom could not be used because the bath is in the way at floor level, and the bathroom window takes up the full width of that wall above the bath. There did not seem to be any good solution, but then Arthur suggested I could use a "thru-ceiling" fitting (in other words, a thru-wall fitting with a shorter piece of threaded pipe) instead. I wish I had thought of that 2 years ago!

I have now modified my setup accordingly. You can see the fittings I used for the ceiling in Fig. 2a to 2c in the details page. My setup now looks like this:

Third and final Big Bucket configuration

The pump-to-garden hose now goes from the pump outlet up to a thru-ceiling fitting, through the ceiling space, then down out another thru-ceiling fitting in the eaves outside the bathroom. This hose normally remains connected to the pump outlet, and the in-line tap just above the pump normally remains open, but this tap will prevent back-flow of old water if this hose needs to be disconnected from the pump for any reason. The part of the pump-to-garden hose that takes the water from the fitting under the eaves to the garden also normally remains connected.

I used opaque hose (actually a white washing machine hose) for the part of the pump-to-garden hose that goes up the bathroom wall because soap scum accumulates inside hoses used with greywater. This makes transparent hoses look rather black and revolting after a while. Even so, I did use a short section of transparent hose adjacent to the pump outlet so that I can see whether or not water is flowing through the hose. (If the pump has lost its prime, it will sound roughly the same as when it is pumping properly even though it isn't.)

The pump needed to be primed the first time I used this final configuration but, since the bucket outlet is higher than the pump inlet, simply opening the tap between the two and waiting for water to run into the pump took care of that. However, normally the pump does not lose its prime because water remains in the pump and the vertical part of the pump-to-garden hose between uses.

I don't believe how easy everything is now! After a shower, all I need to do is to open the in-line tap between the bucket and the pump inlet and switch on the pump. When the bucket is empty, I switch off the pump and close that tap again. I then briefly open the by-pass tap under the bucket to get rid of the small amount of water that runs back towards the bucket during the few seconds between switching off the pump and closing that tap. That's it!
Sump pump setup...
With a sump pump, you won't need to fit an outlet hose to the Big Bucket - the pump is simply placed in the water in the bucket after a shower. The pump outlet might be permanently connected to a thru-wall fitting, or you might need to bring in an outside hose and attach it to the pump (or bring in the pump, if the outside hose is permanently attached to the pump). Then, switch on the pump, wait until the bucket empties, and switch off the pump. Fig. 8 on the Details page shows an example of a suitable sump pump. (With this particular sump pump however, remember to let the water cool to 35C before pumping.)

About the only disadvantage is that sump pumps will not be able to empty the Big Bucket completely. There will always be at least a few millimeters of water left, which you would then tip down the shower drain. This is good for the water trap seal, but might be awkward if you have a wide bucket. If you want, you could cut a plug hole in the bottom of the bucket and insert a plug, then simply pull out that plug to finish emptying the bucket. If so, you'd need to have the bucket raised slightly, but not as much as with the in-line pump setup.

One big advantage of the sump pump option is that the pump can also be used to pump out used bathwater and, if your laundry is adjacent or near to your bathroom, for laundry greywater as well.

No pump (gravity feed) setup...
If you are lucky enough to have an upstairs bathroom, or at least a significant downward gradient from your bathroom to your garden, and your house layout permits use of a thru-wall fitting, this is probably the best option for you. Set up your Big Bucket as for an in-line pump, that is, insert an outlet fitting and hose in the bottom of the bucket, and raise it so that there is enough space between the bucket and the shower alcove floor for the outlet fitting and hose. Instead of going to a pump, this outlet hose connects directly to a thru-wall fitting, which goes through an outside wall and will need to be as low as possible on the bathroom (or shower alcove) wall. Assuming that the bottom of the Big Bucket is slightly higher than the thru-wall fitting, the used water will start running straight out to your garden as soon as you start to shower.

I imagine this option would work even if the thru-wall fitting cannot be quite as low as the bottom of the bucket, but the thru-wall fitting would definitely have to be lower than the water level in the bucket after the shortest shower you are likely to have. In this case, you would be relying on a siphon action to empty the last of the water from the bucket, so it would probably help to have an in-line tap in the outlet hose from the bucket. Keeping this tap closed until after you get out of the shower should, I think, avoid accidentally disrupting the siphoning process before it finishes.

Note re Automatic pumps...
The ideal setup would be what I asked you to imagine - a completely automated system in which a pump kicks in automatically soon after you start the shower running and pumps the water out to the garden via a thru-wall fitting, and then turns itself off once the Big Bucket is empty. This was my original aim and I assumed such a system would be fairly simple for other people to set up in their houses. However, I could not test out that degree of automation in my own house until last week when I realized I could use a thru-ceiling fitting instead of a thru-wall fitting. Now I've discovered that achieving a completely automated system is far from simple, and perhaps impossible. I now feel bad about asking you to imagine it. The third and final Big Bucket configuration above is almost automatic though...just needing to turn the pump and one tap on and off comes close I think.

Perhaps I should fill you in on what has been tried so that you know what does not achieve full automation.

I originally thought a pressure pump would work well, but that was because I didn't really understand how pressure pumps work. Pressure pumps normally switch on when you open a tap because of the lack of pressure at the pump outlet side rather than because of the water pressure at the inlet side. I knew that Arthur is using a pressure pump with his Big Bucket, but he has to prime the pump every time he is about to take a shower in order for the pump to start. In this case, the inbuilt mechanism that stops a pressure pump when it runs dry switches off the pump when the bucket is empty. I'm not sure if it is a critical factor or not, but the gradient between his pump and what he is watering is close to flat. So, even though a pressure pump is doing the job in Arthur's case, the need to prime the pump before every shower means that his system is only semi-automatic and perhaps requires more intervention than my current setup (the final in-line pump configuration described above).

My local pump supplier suggested that using an in-line pump with a float switch wired into its controller might work. Putting the float switch inside the Big Bucket would only empty the bucket down to the height of the switch (about 2cm) so I set up a separate small plastic box next to and lower than the bottom of the bucket such that the water ran from the bucket into the box and then into the pump inlet, and I mounted the float switch inside this box at the right height to switch the pump off just before the water level in the box fell below the pump inlet (so the pump would not lose its prime). The pump supplier suggested I could use the tap on the outlet side of the pump to regulate the flow so that the small box did not empty faster than it filled (which would make the pump switch off and on too often and wear out the pump). This all sounded rather good in theory, but in practice was a dud! The switch we tried was not robust enough for a 240V pump and burnt out as soon as we switched on the pump. What's more, the pump supplier does not know of a float switch that is suited to my pump.

Even so, I experimented with using the small box between the bucket and the pump just in case I did find a suitable switch in future. When the bucket had a lot of water in it there was a fast enough flow from the bucket to the box to keep up with the pump outflow rate (so that the water level in the small box did not fall below the box's outlet hole), but I soon started to need to restrict the flow rate out of the pump to keep these in balance. This of course made emptying the bucket a lot slower than it would normally be, and also required considerable vigilance. Altogether this makes this float switch idea much less automatic and much more complicated than my current setup.

If anyone does work out how to achieve complete automation, please let us all know how you do it!  (Remember that for a system that starts pumping the water out while your shower is in progress you'll need a pump that can handle something like 43 degrees C.


If you want to have your pump out of sight, the simplest way is to have a thru-wall fitting in your bathroom wall and have the pump outside your house, with its inlet connected to the outside end of the thru-wall fitting. If you use an in-line pump and the thru-wall fitting is low on the wall and near the Big Bucket, the pump will draw the water out of the bucket just as effectively as having the pump inside next to your bucket.

If you want your pump to be inside, you could simply make or buy a pump cover. Or, if you have a vanity unit or some sort of cupboard near your shower alcove, you might be able to install a thru-wall fitting through the back of the cupboard and through the wall behind the cupboard, and have your pump inside your cupboard.

If you use a sump pump, the simplest option might be to just sit the pump in the corner of your shower alcove next to your bucket, put the pump in the water to pump it out, then put the pump back in the corner until next time. After all, sump pumps are designed to get wet! If you can put a thru-wall fitting through your shower alcove wall, then all components of the system would be out of sight when you close your shower screen or curtain.

Once you've worked out how you want to collect the used shower water and pump it out of the house, the next step is to design how you will distribute it round your garden.

1 comment:

  1. I did find a suitable switch in future. When the bucket had a lot of water in it there was a fast enough flow from the bucket to the box to keep up with the pump outflow rate (so that the water.