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Home Carbonation Setup for Unlimited Seltzer

Picture of Home Carbonation Setup for Unlimited Seltzer

First off, there are multiple avenues to carbonate water at home. This is definitely one of the higher cost methods but once set up it's the least hassle. I don't have to buy expensive proprietary co2 cylinders or soda bottles (ie. Sodastream) and I don't have to refill and shake 2L bottles using carbacaps. Those are cheaper alternatives which I've used the latter of for the past 2 years. I had a supply of four 2L bottles of water always stocked in the fridge. I probably refilled them every 5-7 days and it was a noticeable chore since I had to shake every bottle.

This is my particular setup for an “unlimited” supply of seltzer water for a bit over $1000 Cdn to give you some inspiration to complete your own. This project could be a bit over $400 US if you skip some of steps and buy used. I’ve used other people’s configuration as a jumping point while adding in my own ideas to best suit my needs. The centerpiece is the McCann’s Big Mac Carbonator that most commercial soda fountains use. It starts with city water passing through a reverse osmosis (RO) system with a bar fridge housing the RO pressure tank and carbonator. The seltzer can then be dispensed through a beer faucet mounted on top of the fridge. This mix of residential and commercial equipment keeps costs relatively low and the space requirement to a minimum. The only maintenance I have to do is to change the RO filters at the recommended intervals, inspect the pump filter once a year and refill the CO2 tank roughly once every 12-24 months.

Step 1: Tools, Materials & Costs



adjustable wrench

beer faucet wrench & spanner tool (can be bought for as little as $3 and it’s definitely not optional due to to the thin kerf required)

aviation or tin snips

dremel drill /w cut off wheel

angle grinder and jawhorse or table saw (to cut carbonator base)

round nose pliers

crimping pliers

oscillating multi-tool (optional)

serrated bread knife (for carving the insulation)

heat gun (for applying the shrink wrap)

soldering iron

utility knife / scissors

safety equipment such as gloves, eye protection, etc

Materials required & Costs*

$120 - 20 lbs co2 cylinder

$45 - co2 regulator

$150 - 4.4 cu ft bar fridge

$120 - 6 stage reverse osmosis system

$250 - McCann's carbonator

$250 - 2 faucet beer tower with 2x Perlick 650ss beer faucet

~$80-100 - miscellaneous supplies, hoses, tubes and fittings including 1/4" ID braided hose, 3/8" OD poly tubing & various push-fit fittings and stainless steel barbs, hanger strapping, teflon tape, desiccant, pipe insulation, duct tape, spare computer cable or several feet of 3 wire 14awg


$32 - drip tray + drain assembly

$36 - 72”’x48”x3” Roxul Comfortboard (used less than half the board)

$15 - 14’ x 3’ - 7mil shrink wrap

$8 - shrink wrap tape

In the attachment please ensure you understand what each fitting does and that its suitable for your requirements. I take no responsibility for the accuracy of this spreadsheet as there were other components I ordered as well. Consider ordering extra gaskets, plugs, o-rings and a JG tool for easy disconnection of the tubes.

There are multiple ways to cut costs. Buying a smaller co2 cylinder, used bar fridge or chest freezer (converted to fridge) and a used carbonator can cut about $250. If you skip the RO system and use a single faucet mounted directly to the fridge/freezer’s side that could save another $250. Altogether your project spend could be a bit over $400 US.

The prices quoted are simply my costs in Canadian. Your mileage may vary as a lot of my equipment was bought off of Ebay; some used some new. Living in Vancouver offers the luxury of being able to take advantage of both the Canadian and US markets. Any US parcels are simply shipped to Blaine being only a 45 min drive away. As an example, the carbonator was bought unused for about $200 US. It usually retails for double this price even online. If you buy one used, you can save up to another $100.

mattzitz25 days ago
Hi...first of all, let me say that this post has been so incredible. Such great detail and information. Thank you for putting so much time into it. I just finished my set up today and I am so excited. I put it on one shelf in my fridge. I have gas and water coming in and a tap on the door. However, it doesn't seem to be carbonating well. I had the CO2 pressure up to 90 and out of the tap, it came out super foamy. I then turned the CO2 pressure down to 60 and it wasn't as foamy coming out, but it still wasn't very carbonated. I'm using 5/16 line to my Perlick 650ss tap...that was the size that came on the shank I purchased for it. Is that too big? Is there something with the size or length of the tubing that I should adjust?
piyoman (author)  mattzitz25 days ago
I don't think the size of the line from the carbonator to the tap would have that large of an impact on the level of carbonation. I would first ensure that the carbonator tank is properly purged of air before using. Basically, shut off the CO2 and open the valve at the top of the tank to bleed out the air until water comes out. Then you can shut the valve immediately. You can turn the CO2 valve back on. What temperature is the soda water dispensing at? Those are the only 2 factors I can think of that would impact your situation.
geoffbund3 months ago
Thanks for a great article! Really beautifully done! I would love to see better photos of the holes and cuts you made. Did you insulate the holes where you ran the lines? How did you make the cuts for the drip tray? Also, I am not familiar with heat shrink in that form factor. Where did you order it from? Does it have a name brand? Thanks again!
piyoman (author)  geoffbund3 months ago
I just used a drill and dremel with a cut off wheel to cut the holes. It's not that difficult since going through the fridge you just have to ensure you're not hitting any refrigerant lines. I was lucky in that the fridge had the lines running through the sides and not through the top or the back. You can just feel for it to see if it gets hot when the compressor is on. If it does, try to avoid it. If it doesn't, it should be safe to cut through. You're really only piercing the metal sheet exterior and at that point, you can stick something in to dig through the insulation gently to ensure you're not messing with piping. Once through, then again, you're piercing plastic/metal sheet on the inside. I tried insulating with just Roxul but you could use expanding foam or even playdoh around the holes. The purpose really isn't to insulate the holes but rather just seal it so that air doesn't pass through. If you have air passing through, you're fridge will build up frost quickly. For the shrink wrap, I bought several feet of construction/boat shrink wrap off of ebay. It's fairly inexpensive stuff and gives it a nice clean look.
geoffbund piyoman2 months ago
Thanks again! I am in the midst of this project. Got a carbonator from Ebay for $180 and already have Co2 and regulator from previous project. I am struggling a little bit with the fittings. Went to Home Depot and said they don't have anything to fit the fittings on the carbonator. This is my first plumbing-style project but my research leads me to believe I need 3/8 "flare fittings" to interface with the carbonator whereas normal house supply lines are 3/8 standard fitting. I couldn't find your spreadsheet anywhere. Any chance you could send?
piyoman (author)  geoffbund2 months ago
catoni29492 months ago
This is absolutely amazing. I tried to set something up underneath my sink without any sort of chiller and the McCann carbonator wouldn’t really carbonate the water very well. Also tried it with a cheap sink water filter faucet. I want to try this assuming that the water temperature from domestic supply is not cold enough and that and the faucet are the reason the first attempt didn’t work. I have a true kegerator that might be perfect for this application. My questions are as follows:

Based off the pictures it doesn’t seem that there’s any sort of back-flow prevention/vent from Come to the McCann tank, is that correct?

Also I am not really sure exactly where to drill the hole in the kegerator any ideas?

Any guidance, feedback and/or direction you can provide would be amazing.

I can’t get over how outstanding this set up is Bravo
Did your McCann come with a small tube (vent) coming off the connection from the pump to the McCann tank? If so, what do you do with that?
See below
piyoman (author)  catoni29492 months ago
The McCann carbonator has 2 backflow valves. One is located right after the pump and the other at the carbonation tank at the CO2 inlet. This ensures carbonated water doesn't flow into the CO2 tubing and of course, ensures the carbonated water doesn't escape into the household water supply. It has to be higher pressure than the water inlet. You can also look up McCann carbonator parts diagram to view exactly where it is. As it's a commercial unit, parts should be readily available unlike household units where if something breaks, you may as well trash the whole unit.

For the Kegerator, I can't be certain where to drill as I don't have one but I'm sure there's plenty of non-critical spots to create a hole. Leave it off for a while then turn it on to feel around to ensure the spot you're interested in drilling through doesn't get hot. When you drill, just be careful to only drill deep enough to break through the exterior sheet metal. Once through, use a screwdriver to carefully dig out the insulation foam until you hit the interior plastic. If you don't see or feel a thin pipe then you should be good to go to keep drilling through to complete your hole. Good luck!
dseacrets4 months ago
Hello I have been trying to get soda water and been having some problems. I have a Mcann's carbonator which pumps water into the tank at 250 PSI. City water pressure runs up to 60 PSI. I have tried the CO2 pressure at 45 to 110 PSI. I have the carbonator inside a mini frig so everything should be cold. I do not have the second tank like in your article but I feel it still should work. In your article you say to set the CO2 pressure just above the water pressure, does this mean I need to readjust the Mcann's pump to match city water or raise the CO2 pressure? Any help you can give me will be greatly appreciated. Thxs Chuck
piyoman (author)  dseacrets4 months ago
Hi Chuck, I don't believe you can adjust the actual water pump pressure for the McCann unit. I was advising adjusting the CO2 pressure coming out of the regulator and into the McCann unit. The tank should have a float so that once the water levels reaches a minimum, it will trigger the pump to force the water in. If the CO2 pressure is lower than the water pressure, water will flow freely into the carbonator without ever triggering the float and pump. This also means, only water will go into the tank and not the CO2 (thus no carbonated water). When you have a higher CO2 pressure than the household water pressure, every time you dispense some carbonated water, the tank will fill with CO2. However once the water level reaches the minimum point, the McCann pump trigger and will force water into the tank.

To diagnose the problem, first purge the carbonator of air. Close the CO2 regulator valve (0 psi), turn on the water and open the bleeder valve at the top of the tank (black or red flip switch). Take care when opening the valve as water will gush out once the tank is full. I usually place a towel on top with my finger on the trigger to close immediately once I feel the towel getting wet. Once the tank is full of water, turn on the CO2 regulator to dispense at 70-80 psi (assuming your water is at 60 psi). Now start dispensing the water as if you were filling a refreshing cup of sparkling water. CO2 should now be replacing the dispensed water in the tank. You should be able to start emptying the tank until the pump kicks in. If you never hear the pump turning on and you've practically drained the tank twice over something is wrong with the pressures. Either the water pressure is too high or the CO2 pressure is too low. Of course, double check that your pump is powered as well. If you have CO2 coming out of the spout that means the float/pump isn't turning on. If you have a non-stop water supply that means the water pressure is greater than the CO2 pressure. I hope this helps. If you have further problems, please describe in detail what the problem is. If this works give an update!
harryH839 months ago
great setup and detailed build! i've had 6 keg-o-raters over the years and built 5 of them. my latest is way downsized from my old subzero able to hold 4 15.5 gallon kegs. i current only have a small modified chest freezer. it is a 5.2 cubic foot energy star rated with an added digital thermostat. i also added insulation [be careful about how you add insulation] and increased air flow. it is large enough for two 5-gallon kegs, CO2 tank but still has lots of room [eg. a few cases of beer or most to all of the setup in this DIY]. i mention this because 1, i plan to add a soda tap and 2, i recommend folks use a modified chest freezer i have my set to 35F and it only uses about 40 kwh/yr [less than 5 watts per hour]. i've become obsessive about energy savings and i'm currently using less power than my 2kw solar array can put [yearly average not daily]

oh and i might have some cool tap handles for your system let me know
dwhgreene1 year ago

This is an excellent, excellent project. I substituted a kegerator for the mini-frig, which saves some time because kegerators already have a hole I the back for hoses and a hole in the top for a tap. There is plenty of room for the carbonator to set on the heavy duty kegerator floor, and by cutting out some of the wires that make up the bottom shelf - Lord knows why kegerators even come with shelves, but they do. - the RO tank fits perfectly. I replaced the beer dispensing tower that came with the kegerator with a soda draft arm (FMP 104-1070) because they are designed to take the much higher pressure in a soda line (up to 100 psi as opposed to about 10 psi for a beer line). The thing works perfectly. And so timely. It is going to be 97 degrees in my location for the next several days. I'm really glad I completed this project.

piyoman (author)  dwhgreene1 year ago

That's great to hear! A kegerator would definitely be ideal but unfortunately it's pricier compared to a basic fridge. I'm sure it's a much cleaner set up though!

rxjock1 year ago

I assembled a similar system, however, I am not able to get the same amount of carbonation as my Sodastream with psi set at 100. The only difference in my setup is that I am using an old Costco touchless lavatory faucet (item #737669). Could this be the issue?

piyoman (author)  rxjock1 year ago

Yes, it could be. Household faucets are typically made out of brass which is cheaper than stainless steel. Just a word of caution brass can leech into your carbonated water. Lavatory faucets usually have an aerator near the tip. This, as well as the flow control in the handle could agitate the water enough that most of the co2 would dissipate right after pouring your glass of seltzer. Getting a beer faucet would be the best solution but I know the Perlick 650ss can be quite expensive. An alternative would be to use an inexpensive beer faucet and experiment around with different lengths of tubing. Beer faucet have a simple ball valve so the flow is relatively uninterrupted, keeping most of your co2 in your glass before consumption. If you have too much pressure and a short length of hose though (without a flow control faucet) the water would spray everywhere upon pouring. Having a longer length of hose would slow down that flow until you get it just right. What you currently save from buying a proper faucet you may waste in co2 over the life of this appliance. Hope this helps! Good luck!

I created an account just to compliment your write-up. That was professionally thorough. Great illustrations. You thought of potential problems and discussed why you did things a certain way. Bravo!

piyoman (author)  1artstudent1 year ago

Thanks! I hope it gives you inspiration to do something like this in the future!

oughtsix1 year ago

-- I built a very similar system myself. Two tap kegerator on-sale at Walmart (2nd tap is still unused). Brand new carbonator from ebay. CO2 tank and regulator from 2 liter shaking days (My kegerator came with a second CO2 bottle which is nice for always having a spare full bottle).

-- is a great place for the "STAINLESS STEEL" barbed / flare fittings, nuts and washers and crimp clamps. Be sure to pick up plenty of extra crimp clamps as they are impossible to find any where else and you are likely to have to redo a barbed connection or two.

-- You are not supposed to use brass where it will contact the carbonated water as carbonated water is acidic and will leach copper out of the brass giving you a cup fill of copper water.

-- The stupid beer taps ARE 3/16". I could not find 3/16" tubing anywhere or 3/16" barbed flare fittings anywhere. What I did was boil the 1/4" reinforced vinyl tubing until it was nice and soft then I quickly clamped it on the beer tap using 2 of the pinch clamps.

-- I initially just used the 3/16" clear vinyl tubing that came with the kegerator... until it burst on me sending water everywhere... including all over me.

-- I could never get ice cold seltzer without having the water in the pump freeze. I had to mount the pump to the back exterior of the kegerator and extend the wiring into the control board mounted to the carbonator tank inside the kegerator. I have never had a frozen pipe / pump problem since and I get sub zero carbonated water (Carbonated water has a lower freezing point than non-carbonated water).

-- I used polyethylene tubing from under my kitchen sink to the pump then from the pump to the tank. My first barbed / compression fitting at the pump had a very slow leak... just an occasional but annoying drip. The second time I crimped this connection I boiled the end of the polyethylene tubing first to soften it then crimped it. Crimping the heat softened tubing has kept the leak at bay.

-- The other problem I have is since I am on well water the well pump will spike the household water pressure to 60+ psi right before it shuts the pump off. This is enough to fill the tank and force out the C02 giving me weaker seltzer than I like. I have a water pressure regulator I am installing to alleviate this problem. On the plus side I have great tasting well water so I don't use a reverse osmosis purifier even though the house came with one under the kitchen sink. I do have the kitchen fridge plumbed through the reverse osmosis filter with gives clearer ice cubes but I don't care for the taste of the purified water as much as the well water.

-- I like my seltzer with a twist of lemon or a twist of lime. A bit of grapefruit juice is also good. My daughter likes the Italian syrups, lemonade mix or even a bit of Koolaid powder. But for the most part we both drink mostly straight seltzer water. We both drink at least a liter a day and I am so happy to no longer hear... daddy, can you mix up a bottle of fizzy water for me please?... usually the second after I sit down in my easy chair!

piyoman (author)  oughtsix1 year ago

Thanks for sharing your experiences! I'm sure others will also find this helpful. I also had some problems finding the exact right crimp and hose combination but I just put 2 on and crimped it really tight. Works like a charm!

GeoNOregon1 year ago

Just a note about teflon tape and 'sealing'. I, too, thought teflon tape was for creating a non-leaking threaded joint... that is, until I read a posting on a professional plumbers' forum.

Much to my surprise, I learned: teflon tape is not intended for, nor should it be depended upon for a seal. The purpose of teflon tape is to supply lubrication to the threads of the fitting, so the fitting can be tightened to a leak free state without galling/damaging the threads.

I have since confirmed this info with other sources.

I was about to build a 'shake the bottle' carbonator for my wife's addiction to selzer when I discovered my former restaurant owning neighbor had included a brand new McCann Carbonator in a pile of stuff left over from his restaurant days. I already knew he'd given me a CO2 bottle, (dang, no regulator, tho!), but I hadn't paid much attention to the pump thing he gave me. I was planning on turning it into a freon collection station, but NOT any more.

Filtered water from our existing water filter system, and plumbed through the spigot on the front of our new side by freezer/fridge. Should be a piece of cake, and THE way to go.

For those of you who don't have generous neighbors or the money to buy a McCann setup, I did come across something which MAY eliminate the need to 'shake' the liter bottles.

Amazon has these porous stones, (like the one's used in air systems in aquariums), of various micron pore sizes. (I think they are called aeration stones.)

Install a correctly sized one on the end of a piece of tube attached to the inside of the two liter 'carbonator cap', with the aeration stone positioned at the bottom of the liter bottle. When the CO2 is forced into the bottle, it is at the bottom and, because of the stone, the molecules are small.

As the CO2 molecules pass up through the fluid, they should associate themselves with the liquid molecules, and make the fluid carbonated. That is the theory, I haven't tried it, but it sure would be shaking a dang two liter bottle.

Hope this helps someone.

I just did my own "larger capapctiy" setup (will be doing a write up soon) and added carbonation stones to the gas in dip tube. It does enhance the carbonation. I leave it in my system and let the gas flow through them constantly maintaining pressure.

Fastnate made it!1 year ago

I made one and it turned out awesome! I love it so much. Mine has a couple of differences from your design such as leaving the Mccann carbonator as it came since it all fit just barely in the bottom of my 4.4cu ft Magic Chef mini-fridge, and also putting the last RO system filter INSIDE the fridge so that it could be the last filter the water passes through before going out the still tap or into the carbonator.

I'm planning to make a nice wood top that incorporates a hot water tap in the future so this can be a station for beverages of all kinds! Right now it's sitting right next to our buffet/coffee bar and it goes perfectly!

Thanks again for all of the good tips!

piyoman (author)  Fastnate1 year ago

Looks great! It keeps it simple when the carbonator can be kept as-is. I was also considering putting the final filter between the tap and the RO tank but with limited space I just chose to leave all the filters outside of the fridge. I haven't noticed any unusual tastes from the tank. If you can share some pictures of inside the fridge too it could give others additional configuration options. Thanks for commenting!

I should also note that I didn't need to bend down the evaporator/freezer section either!
Also I would highly recommend the APEC water RO system that can be found for $200 or less on Amazon. I got mine as a Amazon Warehouse deal with damaged packaging for like $140ish. And everything inside was perfectly fine and very well packaged.
I was very lucky to find my Mccann carbonator and CO2 tank/regulator on Craigslist for only $125 haha. So that saved a TON of money and really made the project worth taking on.
Also I hooked my cold water supply to a Y connector off of my washing machine faucet and then ran the water line through a wall. I purchased a garden hose 3/4" to 1/4" quick connect adapter from for a few dollars to connect to the Y connector off of the washer.

xtianseel2 years ago

Since doing this, are you still using the setup? Have you had any issues with refrigerating the electrical components?

piyoman (author)  xtianseel2 years ago

In step 12 I gave an update 3 months ago. It works great with no issues refrigerating the electrical components or pump motor. Good luck!

seltzerkeg2 years ago


Many thanks for this wonderful and detail how-to. I am inspired to try this. I have 2 questions, my apologies if I missed them.

How are you connecting the 3/8 inch od tubing, from the water tank, to the beer faucet? I understand that beer faucets, are setup for 3/16ths inch lines?

How has the beer faucet worked out, in the long run, for dispensing still water? I have been warned off of doing this, but your great tip, about the Perlick flow control faucets, has me ready to go.

Thank you in advance, have a wondrous day and Pura Vida.

piyoman (author)  seltzerkeg2 years ago

There's an adapter that converts the 3/8" OD tubing to a barb fitting so I can attach 1/4" ID hose directly. This is for the flat water faucet -

For the seltzer line, I just connected the 1/4" ID hose directly to the carbonator tank using a 3/8" swivel nut to 1/4" barb connector. No leaks whatsoever.

The system works great. It's been flawless since I posted this instructable. I've refilled the co2 tank once 3 months ago and I also changed out the RO sediment filters once. Everything has been working fine without a hitch. Good luck!

HonAmish2 years ago

You have inspired me to build this for my wife with your great description! Unfortunately, I bought a used carbonator and the plug for the electrical connection between the float and the pump is missing on the pump side. I was thinking about a direct hard wire (which would make disconnection difficult) or replacing the plug with a standard three prong. Any thoughts?

piyoman (author)  HonAmish2 years ago
Good for you! I'm glad this build is helpful to you. I think either hard wiring it or replacing the connector with a standard 3 prong is fine. Whichever works best for you. Since I've assembled it I haven't found any need to take it apart. If you hard wire it means that one less thing to worry about if anything goes wrong. Though having the ability to disconnect the pump could be useful if you need to change/manuever anything around. When I was hooking up my system I forgot once or twice to connect the pump which made troubleshooting a tad difficult. Doh! :)

Thank you so much. I think I'm going to try with a 3 prong to make sure I'm able to get it positioned the way it works best.

JohnV1133 years ago

Hi- am in the process of opening a small soda fountain shop and noticed the "soda jerk" arms are quite expensive compared to a beer tower faucet which are not that costly. I noticed in your instructable that you are using a beer tower to dispense your seltzer. Is this able to be done???? do you know why there is such a difference in cost of the apparatus?? Any info you can share would be greatly appreciated. Thanks

piyoman (author)  JohnV1133 years ago

The only feasible beer faucet that I found was the Perlick 650ss as it has a
built-in flow control. This will allow you to dial down the high pressure of the seltzer without requiring any additional hardware. The difference in costs is most likely due to supply and demand. There just isn't enough home users that desire a dedicated seltzer setup thus the hardware that exists geared primarily to commercial establishments.

Beer enthusiasts however, is a different story. With the homebrew market expanding and the lines being blurred between commercial and home users this has driven a thriving market for all sorts of beer supplies. Luckily seltzer users can also benefit.

Hope this helps!

belsey4 years ago
This is a great instructable -- thorough and clear! A few years ago I researched this but finally opted NOT to try, after one person I spoke to mentioned his experience with one of those tanks improperly installed blowing through three floors in an apartment building... So I chickened out. Maybe if I had seen such a good instructable at the time I would have mustered the courage to try.....
piyoman (author)  belsey4 years ago

Thanks Belsey, yes it's a bit unnerving dealing with water that can flood your house and high pressure co2 but as long as all the connections are secure and snug it's fairly straight forward. You can also dial down the pressure on initial testing with something lower like 30-50 psi just to ensure everything is airtight.

belsey4 years ago

Isn't this your first instructable? You should definitely enter it into the first time author contest

armorer2434 years ago
Nice write-up! An alternative way to go about it is midway between your setup (which I wish I had the money to do) and shaking bottles (which I hate to do).

I purchased a corny keg and filled it with about 4 gallons of water. I placed the keg into a chest freezer converted to a kegerator. Then I hooked a CO2 line into it. That's it. At about 16psi the chilled water absorbs the co2 without agitation and when the tap is opened it dispenses beautifully. The only drawback is that it takes a couple days to reach full CO2 saturation. But then again, it takes me a month to drink 4 gallons of soda.

Again, great inscrutable! When I get the cash saved up I am definitely making one like yours.
piyoman (author)  armorer2434 years ago

Thanks for your comments. I also looked into your suggested setup but moving, refilling and waiting didn't appeal to me. As I'm practically starting this build from scratch I'd still have to buy the corny kegs and if that was the case, the cost of 2 (one active and another carbonating) is almost equivalent to buying a used carbonator. I've updated the cost section to include a blurb on savings though!