CO2 Injector?

[DeathWarp]

Does anyone have a good link, or could even tell me how to make a simple co2 injector. I keep hearing all these things about 2L bottles and whatnot, but I truely dont understand what you need to do.

co2 for dummies!

 

[dskidmore]

Do you mean CO2 generarator or diffuser? On the basic level, both are very simple.

Generator:
Drill a hole in a bottle cap slightly smaller than your airline tubing, cut the tubing on an angle and use pliers to pull it through. (This works best with silicone tubing.) Put the cap on the bottle. Ta-da, you have a CO2 generator. Fill the generator with a cup or two of sugar, a little yeast, and alot of water. (I also put some gravel in mine to keep them from tipping over easily.) There are lots of diffrent recipies online, pick one and stick to it, and you'll get a feel for how often you need to recharge the generator.

Diffuser:
The simplest thing is stick the tubing from your generator into your filter inlet. The impeller will break up the bubbles, and the bubbles will get caught on the filter media and have a long time to disolve before rising to the surface. Next easiest is a fine pore airstone. After that you can get fancy with methods of trapping the CO2 underwater, or slowing it's ascention, or circulating water over it.

 

[DeathWarp]

thank you... much simpler than I had imagined. When using the Generator, do you tip the bottle upside down and run the tubing into the water? (im very sorry if that is a completely stupid question) or does the bottle remain upright with the tubing in the water?

 

[dskidmore]

The generator should be completly seperate from the tank, with the airline leading into the tank. Leave the bottle upright. The yeast will eat the sugar to create CO2. As CO2 is produced, it will build up pressure and force CO2 out the tube into the aquarium. You don't want the yeast solution pouring into the tank, so make sure the bottles are securely upright. (That's why I put gravel in mine.)

 

[Lonewolfblue]

Some people also use a 2nd bottle, with 2 holes drilled, and leave it empty. Run the air tube from the main bottle into the 2nd bottle, then another tube from the 2nd bottle to the tank. Basically what this does is if you do get any yeast solution in the tubing, it will only go to the 2nd bottle and not into the tank. Kind of a protective device.

 

[DeathWarp]

Ahh sweet... that's 100% everything I needed to know, thank you SOO much. I'm going to start on this tonight, because my plants are starting to give me dirty looks whenever I walk by my tank

 

[dskidmore]

Some people also use a 2nd bottle, with 2 holes drilled, and leave it empty. Run the air tube from the main bottle into the 2nd bottle, then another tube from the 2nd bottle to the tank. Basically what this does is if you do get any yeast solution in the tubing, it will only go to the 2nd bottle and not into the tank. Kind of a protective device.

I remember in 6th grade science class we did that. We did a series of experiments creating gasses, and some of the reations were rather noxious, so the gas was forced to bubble into some water before it went up the output tube for analysis. (I hadn't done my homework, and plumbed the thing backwards, the teacher caught me before I started pumping water all over the floor.)

 

[Burks]

I just set my DIY CO2 system up about 5 minutes ago.

It consists of a 2L Pepsi bottle, some silicon tubing, and is attached to the filter inlet. Really simple right now but I only have one plant.

If you don't mind me asking, what would the next step be besides a pore airstone? I keep seeing these "powerheads" pop up in DIY CO2 write-ups (pretty cheap, checked them out today).

Edit: Getting a good amount of bubbles now. My only problem is when the bubble hits the impellar it makes a funny noise. Doesn't really bother me if it's for the fish and plants benefit.

 

[dskidmore]

There are all kinds of diffusers out there.

One step up from the fine-pore air stone would be a glass diffuser. They can create a fine mist of bubbles, that are easily carried away by a current.

There's the "bell" diffuser, that just traps the CO2 under water until it is dissolved. This isn't such a great option with DIY CO2, as the excess CO2 doesn't get a chance to escape until the bell is overflowing (underflowing?) and burps out a huge bubble.

There's the "ladder" diffuser, that allows bubbles to work slowly upwards along a series of ramps.

The ones with power heads actively push water down over the CO2 bubbles, increasing the suspense time of the bubbles. This is often aided by bioballs or gravel, that the bubbles get trapped on as they rise.

 

[rich311k]

My inline diffuser does a great job. I have never had better and more stable levels.

 

[Burks]

My inline diffuser does a great job. I have never had better and more stable levels.

Is it a DIY job? I'd be interested in making one.

I've found a design that may suit my needs for a little bit: Design Not pretty but it should get the job done.

 

[SkullJug]

The best diffuser I've made ran from a power head. I have made a diagram but still have to get it hosted - Here is the instructions. If you do it right you can dissolve 100% of your c02. I'm pretty proud of it acutally.

1. Cut a small piece of UGF tubing(The clear uplift pipe) - about 3-5 cm long and silicon it to the under side of the lip of your tank. IT should be airtight and extend below the water line.

2. Attach the outlet from your c02 generator bottle so that it bubbles into the the UGF tubing.

3. Attach a venturi fitting to your Powerhead (This is the one used to blow bubbles) and have an airline tube running into the the UGF tubing. This will suck the CO2 into the power head without putting any pressure on the generator bottle.

By itself this will work pretty well, but if you want to disolve the CO2 completely....

4. Take two peices of UGF tubing about 6 cms and 10cms. Cut a hole in the middle of the 6 cm piece and round off(inverse) the top of the 10cm tube so you can join the two peices into a sealed T shape. The 6cm piece will form the cross peice and the 10cm the vertical. Seal one end of the cross piece (I found a sports drinks that had this clear plastic cap that fit perfectly - Nice drink too). Now attach the open end of the cross piece to the end of the powerhead.

You might need to play with the length of the vertical piece, or even pack it with foam to get the c02 to dissolve completely(Avoid foam if you can, it will harbour anoerobic bacteria) The power head will blow the C02 and water in the cross peice and literaly create a hurricane that dissolves c02 like you won't believe. This system has the added benefit of ensuring that you yeast/sugar mix cannot end up in your tank.

 

[Purrbox]

My inline diffuser does a great job. I have never had better and more stable levels.

Is it a DIY job? I'd be interested in making one.

Rich's Inline CO2 Reactor is DIY, however I'm the one that built it for him. For a picture check out this thread, it's the "Monster" CO2 Reactor about half way down. I used these plans with a slight modification so that the bottom has a flat spot that can be rested on a shelf. I'm using miniture versions of this same CO2 reactor on my Nano's. For pics and details check out this thread. They are fairly easy to build, the hardest thing is getting used to working with PVC if you never made anything with it before.

 

[Thebluyak]

Ive heard that if you run the CO2 into the inlet of your filter the impeller can be damaged and the ruber O rings will start to fall apart from all the excess carbon. Just a thought id pass along, no idea of the validity of it but better safe than sorry.

 

[dskidmore]

Carbonic acid (CO2 disolved in water) can cause some flexible plastics to get stiff and not function as well as they did. Carbonic acid can in high quantities (like in soda/pop) break down metals over time. That said, I've never heard anyone say that they broke thier filter by running a CO2 line into it. Probably because most of us either run minimal CO2, or upgrade to something better after a little while.

 

[SkullJug]

Carbonic acid (CO2 disolved in water) can cause some flexible plastics to get stiff and not function as well as they did. .

You could get around this by setting your diffuser on you outlet instead of intake - Just make sure the current is dropping through the diffuser - not rising.

I really like your design purr - I'd put one together myself but I run a sponge filter with a power head anyway(It sits in front of the filter inlet - I just clean the sponge when I do my weekly pruning - Extends filter cleaning massively) so I don't really need inline. Awesome build though, I really like it. The only thing that would concern me is that doesn't this have the potential to end up with the yeast mix in your tank (not much of a chance but this happened to a friend of mine - not pretty at all)

 

[Purrbox]

To avoid having yeast mix make it to your tank you just need to place a separator bottle between the CO2 generator bottles and the CO2 Reactor. Another option is to use a yeast like Champagne Yeast which sinks instead of floating, minimizing the chances of it getting into the tubing. Or if you're really paranoid, you could do both. Of course this CO2 reactor can be used with pressurized CO2 which avoids the problem altogether.

 

[dskidmore]

I just put a handful of gravel in the bottom of the bottles, so the bottle has little chance of tipping over. I also in winter put the bottles inside a 10 gallon waterbath, further reducing the chance of tipping. Beoynd that, depend on your regular mix to foam about the same amount each time, and don't overfill the bottles.

 

[SkullJug]

I am using a wine yeast and it works really well. I strongly recommend it, I hadn't acutally thought of the fact that it is safer as well, I just use it because it lasts longer (Alcohol tollerant). I am actually about to post the beginings of a new idea in relation to this.

Once again purr- great diffuser, a friend of mine is just venturing from cichlids to planted and doesn't run a powerhead- I'll definately point him towards your design.

 

[Lonewolfblue]

How long does it take between the time you mix the batch and you see bubbles coming out of the airstone, if that's what it's run to? I currently set one up with 2 1G Apple cider bottles, as they have solid caps and a nice big flat bottom, so tipping isn't a factor.

Edit:
Took 30 minutes to start bubbling strong.