Showerloop is a water filtration and purification system that recycles shower water in real time allowing you to shower with hot water for a long time but only use 10 liters of water per shower (normal shower = ~6-10l/min) and a fraction of the energy (around one tenth) compared to a normal shower. The device can be installed inside or outside of a shower stall or bathtub. The main components are a pump, sand and activated carbon filters and a UV-lamp. The system weighs around 20kg and is made from transparent acrylic, steel or plastic pipe connectors and copper, plastic or rubber tubing.

The total cost of the most simple version has cost me around 600€ (~$655 US) depending on availability and pricing of local materials and the components used.

The filters can last as long as two years (but more like 1 year) with daily use but depends on the behaviour and general dirtiness of the user/s. The sand filter can be washed, the activated carbon or AC can be regenerated but only at high temperatures > 500 degrees C or composted and the UV lamp should last for thousands of hours but can be recycled and replaced like any other CFL.

The basic build of Showerloop is incredibly modular in terms of placement, materials selection and aesthetics. The only constraints come from the ideal filter dimensions and the power output of the UV lamp both of which are explored in the bachelor thesis ShowerMagic : A Hygienic and Eco-Efficient Real Time Greywater Reuse System for Showers found here: https://www.theseus.fi/handle/10024/76148

If you will build, built or are manufacturing Showerloop's or something based on this document please help us to continue working on it by donating to us, buying the KIT or parts or otherwise partnering with us. Without your support we will work our butts off to help you save the world!

Because the water should always be cleaned 100% or as close as possible the table NTU Reduction (%) above should be consulted if using different dimensions for the filter. NTU stands for Nephelometric Turbidity Units. It is a unit of measurement for the amount of particles floating in water. Drinking water has a value under 10 NTU, generally around 4 and visibly dirty water has an NTU over 15-20. NTU is measured chemically or optically. We have some design ideas for an open-source sensor, or several and would like some making them.

Although technically a 10W UV lamp can be sufficient for the removal of E.coli which is used as an indicator of water quality, other bacteria and viruses are much more potent and so we chose to use very high concentrations of UV light in order to create a safety buffer. According to our research the powerful lamp is more than sufficient in removal of bacteria even when the filters fail which means that even if the water looks, feels or tastes funny there shouldn’t be adverse health effects due to microbial action. If it does though, then it’s time to check, maintain or replace the filters. Using multiple UV lamps might be a good way to both ensure that the water is always bacteria free and all excess heat goes into maintaining water temperature.

Step 1: What you'll need


See poc21 component list above


  • laser cutting, CNC or manual routing
  • pipe working skills or handling rubber tubing
  • basic proficiency in building and assembling things
  • basic understanding of how water flows
  • patience and determination


  • one or two people
  • a working shower
  • several square meters of workspace
  • basic power tools, hand tools and the ability to use them
  • towels (there will be water everywhere in the beginning!)


MEDIUM - HIGH : Anyone with a DIY mentality can do it


  • 10+ hours finding materials
  • 1-3 hours laser cutting
  • 1-3 hours pipe bending
  • 2 hours assembling filters
  • 2 hours connecting piping
  • 2 hours for mounting
  • 2 hours for electronics assembly
  • 20 hours for everything we forgot... fixing leaks and other stuff
  • total = 22-42+ hours, with the kit 4-12 hours (and way less hassle)


  • Material costs= ~600 +- 300 Euros (~$655 US)
  • Tools if you don’t have them ~200 - 300 Euros (~$275 US)
  • general costs for material
  • costs for special services such as Laser cutter or CNC. As a reference, our Fab Lab costs for a recent build totalled around 40 Euros (~$45 US) but included components. This figure will vary, and you should contact your local Fab Lab/ maker space for their advice on this.



  • Router or laser cutter* or CNC machine, hand drill.
  • Blade saw (for cutting the filter tubes)
  • Drill (wood/plastic drill bits, circular saw bits)


  • Monkey wrench or 17, 21, 24 mm spanners
  • Pipe wrench
  • Ruler or measuring tape, straight edge, pen
  • Pipe bender (if you work with copper)
  • Hand saw (metal and wood), scissors, pliers
  • Allen driver, screwdrivers
  • Small vice

If you use copper pipe then a blowtorch and pipe bender.

Don't forget to always use safety gear: safety googles, ear protection, gloves and ventilated spaces.

OUTPUT aka Trash

Left over acrylic sheets, and ’little plastic cones’ copper pipe or random hose, paper, cut pipe and threaded rod, packaging material, tools and components you might never use again though all of them can be used to fix Showerloop - it’s always good to have tools :)

<p>Clever. I do the poor person's version of this. I have a portable pump shower with a filter built in which I use with a bucket of hot water then have the shower curtain draped so almost all the water is directed back into the bucket. </p>
<p>Nice </p>
<p>Bonjour, please forgive my bad english :)</p><p>This idea is amazing, I want to install it in my home, two adults and two kids, we use daily too many water ... I don't have enought skills and tools to build it by myself ... the kit should be perfect... but I have many questions about how to install it in the actual shower... and it's very expensive for us, so I can't risk a failled system... (because of my lack of skills)</p><p>... A half way system couldn't be developped? A simple heating loop not filtered and use an extra rinse water? I wonder about the recovery of the water out of the plumbing configuration to direct water to the loop or the evacuation. I haven't found this information / scheme. If I were to get critical is to make explanations accessible to people with very little or no skills at all ... only way to share this great idea to many people as possible ... I want to evolve, but I need much more informations and help than what you already give ^^D</p><p>By the way, a uge thank to the work already done and please keep going :)</p>
<p>I'm excited to make a semi-portable shower, complete with solar water heating, for daily showers at Burning Man next year.</p>
<p>If you get me tickets there I'll help you build it ;)</p>
<p>This is an awesome project. Thanks for sharing ! I'd like to try it out. I'm in an isolated house with a water well not connected to sewers and the septic installations are getting old. I'm not sure if there's space left for new ones. I might end up with a sealed tank which is very costly to empty.</p><p>I was thinking if that system to be extended to another context, such as a washing machine for instance. So that I could do several washes using the same water.</p><p>Would it be the same kind of system but larger ?</p>
<p>You would need a very large holding tank. Since most machines only run two wash cycles per wash (one with soap, one to rinse), double the amount of water your washing machine is designed to hold, then add about 1/4 of that as extra. <br><br>Almost all laundry soap you buy now is HE (High Efficiency) and shouldn't be any more issue than whats used in a bath. </p>
Great, thanks for the insight ! Much appreciated !
Yes I think it could work. Since there is some period between washes (?) you may not need to scale up the system but just run the water through several times. Haven't studied that type of dirt and detergent load but I'm sure with some modification you could make it work.<br>A storage and settling tank for instance would capture and separate some material and a way to skim off floating oil/grease would also help.<br><br>
<p>Nice, thanks for the reply and again, very nice project !</p>
<p>Quote: &quot;Without your support we will work our butts off to help you save the world!&quot;<br>I'm not sure that's what they mean, but hey - nice project.</p><p>Wonder how much one would save when all is added up.</p>
<p>Hahaha, oh no. I meant it the other way around as I was hoping to setup a donation kind of thing but I just don't know how to ask for help :/</p>
<p>You should make a Kickstarter or a similar crowdfunding campaign in order to expedite the research of this amazing device. It would seem that you have ample supporters.</p>
<p>A very interesting project. I have one question: Does the water get very cold after showering for a while, because I do not see any heating or adding hot water. Is that correct?</p>
Yes you're right. I'm trying to find ways of avoiding electrical heating - so using solar thermal or using a heat exchanger to extract waste heat from another process. The benefit is of course that a really small and inexpensive system is enough.<br><br>The simplest thing to do is to add a some more warm water from the tap every now and then which does reduce efficiency, but it's still better than the 1:1 we have now. <br><br>Though not for everybody, you can also just start with hot water and let it cool down over time and leave once it get's uncomfortable. If the shower stall is well insulated this can be at least 5 minutes.
<p>Always use PEX and/or Shark Bight (or is it Bite?) over copper or PVC. Cost far less, easier to use, faster to install, works very well with existing copper, plastic or galvanized and won't burst in freezing situations nearly as easily. Overall, this is a great money saving, long run DIY. I didn't do this, but I did make one that with the push of a button, your lightly filtered water (using GREEN/ Organic soaps) could be rerouted to your yard and/or garden that worked nicely.</p>
<p>I'd want to try PEX but you need all those special tools to get started with it. Do you know of any affordable options?</p>
Negative, there are only two &quot;special&quot; tools and they are just to make things go much easier, not needed but really a big help. They are the pipe cutter, which is just a large, very sharp bladed scissor like item and the release tool which looks like a plastic &quot;C&quot; for the times we might need to make changes (commonly called mistakes), in the length, adaptors and/or routing of the pipe. Nothing too &quot;special&quot; but nice (and cheap) to have. No glue, cleaners, no fuss, no muss. There are release tools for each size of pipe, as I remember about $1 ea. and to make things look really sharp they have nail type clamps to mount everything. There are 90 degree adaptors, length connectors, changing size adaptors, adaptors for attaching to galvanized or faucets, basically everything you need to plum any home or business in a third of the time. The pipe will freeze but the difference is that it expanse without bursting then when it thaws, it's all good to go, no problems. And with the quick connector, you can hook up to any copper or plastic with NO glue or welding. THIS STUFF IS GREAT.
<p>Thanks for the information. It looks like the easiest option. Do you know about the environmental impacts of it compared to copper? Because you can recycle metal. Plastics not so much. The overall footprint might be smaller for lightweight stuff when you count production and transportation. Mass = fuel.</p>
<p>Pex is very versitile. I have had customers change their mind and had to pull it a part, very easily, and reused it in other areas. I am sure the shelf life is forever or more, but like I said it can be reused in many other prodjects, then reused again, if need be, or left alone for the duration. Which means little to no environmental impact when used properly.</p>
<p>You don't need special tools anymore. The SharkBite couplers are amazing. They are push on connectors that can connect to copper or pex or connect the two. I used them when I had to replace a hot water heater located in a crawl space. They were a godsend. All you need is a cutter to make nice clean ends.</p>
<p>I'll see if I can get them to Finland.</p>
<p>that is not a flow regulator.</p>
<p>I think you're right. We just had to come up with a name and it stuck. What would you call it.</p>
A flow regulator...well google it. it limits the volume of liquid and pressure, usually by a mesh or frame with holes in it...in fact your compression disks are pretty much flow regulators.<br><br>I would consider it an inspection junction, or inspection point.<br>Junction because that's effectively what it does, it allows extra water flow by adding more and more parallel branches, while keeping an easy to find, narrower (and stronger) pipes and tubes.
<p>Ok that sounds reasonable. Will add it. </p>
Activated carbon can adsorb and neutralise gases. However it does not have this function when wet. It will still have a filtering property, but no more than sand of the same particle size.<br>Nice project though, very well described. <br>I have always wondered why a simple heat exchanger is not available to fit under the shower floor to take the heat from the exited water to warm up the cold water used in the mix. Anybody ever tried to make one or seen a product like this?
Yes, there are a few out there -http://shower-save.com/ for example (no affiliation)
<p>the carbon wont do anything wet.<br>for the material filter, what micro size are you going down to? would dairy &quot;sock&quot; filters be a more convenient way to get them?<br>have you considered zeolite for a primary particle filter, it backflushes better than sand.<br>What temperature does the water re-feed at? I've got full solar water, but would love a way to move up to a 300mm shower head (or multihead shower)...without the excess wastage. (hoping also to move to prodominantly rain fed water supply)</p>
<p>Carbon does work when wet and is commonly used in waste water treatment plants and even aquarium filters.</p><p>Zeolite seemed too expensive for me but Finland is a small place with not much on the shelves so it may be more affordable in other places. I totally encourage people to try things out. If we could codevelop this around the world we will have showers that use practically no water but feel like a water fall.</p><p>Water re-feed rate depends on the conditions of your bathroom as the heat is dissipating into the air, wall and floor.</p>
<p>you're going to need a good UV filter to deal with the bacteria, fungus, and algae you're growing in your human cell medium with it's plentiful light supply. (water + light = algae, unless water is very sterile.</p>
<p>why not make a kit and try to raise money on headstart ?</p>
<p>We're making a few KITs now until we get things ready :) </p>
<p>please let me know when it will be ready. i would like to buy it. </p>
<p>Nice build, and interesting papers.</p><p>Have you or do you plan to profile the actual contaminant load produced by a person in the shower? (Seems like the kind of experiment that might lead to some fun stories.)</p><p>I'm curious about contaminant concentration vs time, it would be interesting to see analysis of water samples taken once per minute from the operating shower over a 10 minute run, both with and without a person in the shower.</p><p>Have you measured filter performance over time to verify that performance remains acceptable after a couple of hundred simulated showers?</p><p>What's the embodied energy of the components used in construction, and how long do you anticipate that it will take to reach energy break-even for your market area? Large scale water treatment is likely fairly energy efficient per unit volume of treated water relative to small-scale treatment, so I'm curious how quickly the water and water treatment savings become positive.<br></p>
<p>Hey, great questions. </p><p>I would love to profile contaminant loads but I don't currently have access to a lab. All our test water experiments were based on the highest detected values for shower water based on the literature we could find. While not detailed in this instructable (coming next time), we've added t-connectors and valves to allow a user to backwash and bypass the filters, this way larger debris can be washed out and pre-washing can be made possible. So if you fell in a pile of mud, you could rinse off without activating the filters. This has made it a bit tricky to define just how long the filters actually last for because it's user specific and we're just starting to collect user data in parallel to lab experiments. The UV handled bacteria very well even without filtration which was surprising but also encouraging. </p><p>We had some MIPS (material input per service unit) calculations done by an outside party but this was early on in our research and so many of the calculations were based on estimates. We'll hopefully have that for the next instructable as well. The gist was that with a 20 year service life the abiotic input/output 'improvement' was by 1/3 and air emissions almost 1/5th and water was a bit off the charts. </p><p>Large scale water treatment is effective but with Showerloop one can also save energy. This is a good reminder to fix the calculator that we had on our website so you could calculate the potential savings for your own habits, but I'm bad at Javascript so I couldn't get it working. Will add that in the soon-time. For average use cases the ROI is supposed to be around 6 years for a single person in Finland (water at 1.5e/m3 and electricity under 80e/MWh).</p>
<p>Really cool idea. Is there any risk to bacteria (legionella or mold) growing in the filter? Would there be another way to neutralize the sulphates other than the activated carbon?</p>
Im in the process of building a home in a bus to remove myself from the grid. This shower idea could work well for me. Im not sure how i can help support you as im aleady going to need to change up the materials needed to make it cost possible for myself. Ill try keep in contact on how/if this goes. Thank you for the inspiration. <br>James.<br>Whyamiusingthis@hotmail.com <br>
<p>Such an interesting project. Saves water and energy. </p><p>Why not just use some PVC pipe instead of an acrylic tube? Practicality is more important than maker-izing the project. Using LASER-cut parts really isn't required. And who wants a clear filter? Ew.</p><p>Otherwise, really nice work. Concepts will work even for a less pretty version.</p>

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