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DIY regulated CO2 for the nano & pico aquarium

42K views 26 replies 22 participants last post by  GlockWise  
#1 ·
I have big planted tanks. And each one of those tanks has a nice 5lb co2 canister tucked under the stand or around the corner. Out of sight and out of mind I always say. Regulated co2 is sweet.

But in putting together a 5gal nano to take to my office I needed something a bit smaller. Doing it on the cheap I didn't want to shell out the cash for one of those super nice ADA mini canister systems. Plus, I would be locked into their cartridges. Sugar and yeast in a soda bottle under my desk was an HR violation waiting to happen (throw in a ketchup packet or two and you are technically making prison wine!). There had to be something else. Then I remembered those little co2 cartridges I used my bb gun as a kid, a plan was hatched.

Trying to create a piercing device at home wasn't going so hot and I stumbled upon a backup device for the paintballers that uses those cheap little co2 cartridges. Ebay 'emergency co2' and you'll see quite a few. At $20, it was worth a shot.

With my cartridge piercer in hand, a quick trip to LowDepot (either will work) turned up absolutely everything I needed to make a mini regulator for the co2 cartridges. All paintball guns have a 1/2" thread, which is exactly what the unit has. And did you know that in the plumbing section, where all the brass fitting are, they actually have needle valves?

And so it went: CO2 device -> 1/2" female to 1/4" male -> 1/4" female to 1/8" female -> 1/8" needle valve. I was out of the store for under $15, and had everything I needed. Don't forget to pick up a roll of teflon tape, you'll want those connections nice and tight. I picked pink, because nothing says breast cancer awareness like DIY CO2!


Take a look at the photo's to see it all put together. With the relatively low pressures in those cartridges, you can get away with it without any worries. The needle valve looks clunky, and it will take you a little while to get used to adjusting it as it isn't as fine as the ones you might be accustomed to, but it works just fine. Tighten up everything together real nice, and test it out in a bucket of water. The bottom of the emergency co2 device unscrews from the top, you slide the cartridge in and screw it back. The action of tightening pierces the device, and the co2 starts flowing. That $5 needle valve works just fine in holding it back.


At 1 bubble per second, I can get about a solid month out of the 12 gram co2 cartridge (which runs about 40 cents if you buy a box with a few dozen in them - less if you order online). It goes longer if you turn it off manually at night. Sure, when the cartridge is on its last legs, you'll have to adjust the needle valve. But it is way more consistent than making your own CO2 in a jug, and my desk doesn't smell like a bakery!
 

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#2 ·
Great ideas, thanks for the advice! Been looking for a cheaper alternative to using CO2.
I'm happy with using flourish excel for now, but this DIY rig seems rather nifty.

could you clarify what you meant by the following:
CO2 device -> 1/2" female to 1/4" male -> 1/4" female to 1/8" female -> 1/8" needle valve

What are these parts? What are they called, not sure what you mean by "1/2" female to 1/4" male"....
Also, how do you diffuse the CO2 in the tank, what is the tubing connected to at the other end?

much thanks,
d.
 
#27 ·
He left out that the standard size for paintball is 5/8" which is a unique size - I think 1/2" still fits for the 1st thread or so but I will have to try this soon... I have had the parts for years but home depot didn't sell the parts I needed so I never tried it...

Also it's not "emergency" it's "back-up" - it's a "back-up CO2 adapter"
 
#3 ·
Very nice, this breeds life into consistent Nano CO2. If need be you could always put a more precise needle valve inline. But if the LowDepot one works just fine no need to spend more bucks.

Are you sending this through a glass diffuser? If so when the pressure drops does it still work?
 
#4 ·
To clarify, those are the sizes of brass fittings you'll need to purchase. You will basically be stepping down the 1/2" thread size on the co2 unit to the 1/8" thread size that the needle valve needs.

I have been running the line directly into the filter intake, but I'll throw on a diffuser and can report back how it performs over the life of a single cartridge.
 
#6 ·
If by solenoid you mean manually turning it off at night, then yeah. You could integrate a solenoid into the design, but at that point, it's probably best to just get a 5lb CO2 tank and an actual regulator.

I leave the co2 on 24/7 in all of my tanks, and haven't had any problems ever. But that's just been my experience.
 
#8 ·
If by solenoid you mean manually turning it off at night, then yeah. You could integrate a solenoid into the design, but at that point, it's probably best to just get a 5lb CO2 tank and an actual regulator.
I was thinking about an electronically controlled solenoid. Not having to use a big CO2 tank and the associated regulator has its appeal in setting up a small scale experiment.
 
#10 · (Edited)
Ramskip, look at the pictures. Look for the pink teflon tape to separate each piece.
Start at the bottom.
The CO2 cartridge sits inside the black part. The black part has male threads (male means the threads are on the outside) and is 1/2" NPT (this is a standard pipe size)
Then comes a brass part. This one has female threads (Threads on the inside) that screw onto the black part, and the other side of this brass part has 1/4" female threads. This is a 1/2" x 1/4" reducing coupling.
The next in line is a part that has 1/4" male threads that fit into the part I just described, and it has 1/8" female threads that match the needle valve. it is a 1/4" x 1/8" threaded reducer.
The needle valve has 1/8" male fittings on both sides.
The last fitting is 1/8" female threads to fit the needle valve, and has a barbed outlet so the tubing fits snuggly onto it. This piece is a 1/8" thread x 1/8" barb.

If you want to build one of these print the picture and this description and take it with you when you go to the store. Bring a few inches of the tubing you will use, too. Start with the CO2 at the left side of the cart (buy it elsewhere, bring it into the store with you). Find and place the needle valve to the right. Now find enough fittings to connect the two. Now add a barbed fitting that fits the tubing you are using. I am not sure if these stores sell a good tubing that is CO2 resistant.
 
#17 ·
Image


I found this guy, originally intended to inflate bicycle tires. It's called the Red Zeppelin by Planet Bike. There's a valve of sorts on the top to control flow out of the CO2 cartridge, I wonder if the Schrader can be removed and replaced with a needle valve and a nipple?

This thing retails for about 20 bucks, it might be worth a shot to try to rig something up.
 
#19 ·
Do these little tanks have liquid co2, just like their larger counterparts? If so, then couldn't larger tank setups theoretically use similar setups due to similar pressures? It might be beneficial for any of these setups to get a needle valve that is actually rated for the about 850 psi that co2 cannisters with liquid usually have. I called up a few needle valve companies; one guy said I couldn't do it, another said that it's possible, but the co2 output wouldn't be consistent. Sounds like dolla is already manually adjusting output and this isn't too time intensive. Does anyone have thoughts on this?
 
#25 · (Edited)
Hey, great idea...

I took your idea and modified it. I'm an avid paintballer, so I had some stuff lying around, for all of you who are going to go get ripped off on 12gram co2 tanks you should probably just think about getting full size tanks with a paintball asa.

This is what I'm talking about:

http://cgi.ebay.com/ws/eBayISAPI.dl...PI.dll?ViewItem&Item=120610465749&Category=16051&_trkparms=algo=LVI&its=I&otn=2
and
http://cgi.ebay.com/air-n2-co2-asa-...-co2-asa-adapter-fill-station-remote-on-off-/280547675496?pt=LH_DefaultDomain_0

It doesn't have to be those exact ones, but as far as I know, all of the on/offs and just direct air have standard fittings that you can stick those brass fittings in with the needle valve. I would recommend grabbing a cheap On/off though because you'll be able to fine tune it better (unlike my set up which is just direct air) but either works well.

Here is an example of what I made - it ended up like 6 or 7 bucks total for me because I already have the Co2 tank and ASA. Make sure to get some teflon tape to ensure a tight seal.

Image

Image

Image


Again, thanks for the idea! I just run this straight into my diy diffuser now for my 10 gallon tank.

Edit: Also, every co2 tank has the potential of liquid co2 in it. Depends on altitude, temperature, and pressure. But, all Co2 tanks should output 850-1000+ PSI whether it's a 12gram or a 20oz. Output pressure will vary based on altitude, temperature, etc too though.