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]

Originally Posted by 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.

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.