DIY CO2 for dummies

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Aquarium Advice Addict
Dec 4, 2004
I am in the process of upgrading my 55 gal tank. The new light strip should be here by the end of the week and I am anxious to get it all up and running. With the new strip I should be at 2.75 wpg. I have been trying to research DIY Co2 and figuring out how to make one myself but I am so lost. Can anyone dumb it down for me? What exactly goes into a DIY system? Does anyone have a link that shows pictures from start to finish? My husband did some searching last night and after about 2 hours he said it would probably be easier just to buy a unit pre-made. lol

I did find a link that gave instructions but they were vague. "Cut the plastic pot in half and glue a piece of plastic to it." How big of a piece of plastic? Glue it where? What kind of plastic?

During the entire process I would like to do a photo log of every step. But now it is just getting it started. Can anyone help me?
That's where I am at. :) I did read plenty of threads but it is still not explaining anything to me.
If you're not feeling too DIY inclined I've got my DIY CO2 cap sets for sale in the Classified Forum. This would still be less expensive than buying one of those premade sets.

This is one of the best articles I've found on DIY CO2. (I can't open the page right now, but this seems to happen with that site periodically and it should be up later.) It probably gives you way more information than you want at the moment, but the Construction Project gives lots of pics and a very detailed set of instructions.
Not sure what cap sets are for or what they are exactly. I'll keep researching and hopefully come across a site that makes sense and explains to me what exactly I need for a CO2 system. And I may just scrap it all together. Too complicated.
Cap Set is just the term I used to refer the Pop Bottle Caps, Fittings, and Tubing that I put together to use for DIY CO2. All that's missing is the Bottles, Diffuser, and some extra tubing to connect the Cap Set to the Diffuser. If you take a look at the pics in the link it should make more sense. It will also give you a better idea of what you are actually building.

Basically you need either some empty pop or juice bottles. The number and size is dependant on the size of the tank that you want to inject CO2 into. In your case you'll probably want either 5-6 Two Liter Pop Bottles or 3 One Gallon Juice Bottles.

Drill at hole in the lids that is the appropriate size for the fittings or tubing that you will be using. If threading the tubing directly through the cap, you want the hole to be a bit smaller to create a better fit.

Attach the fittings or thread the tubing through the hole. If using fittings make sure the screw snug to create a good mechanical seal. Tubing can then be attached to the connector. For tubing it helps to cut the end at an angle to make threading it through the hole easier, then use an aquarium safe sealant around the tubing to make sure to get an air tight seal.

The tubing from all the bottles can be connected using airline connectors so that all the CO2 can be run through a single diffuser. Run tubing to your diffuser of choice.

I can get you directions for several different types of powered diffusers (reactors) if you need further help with that part as well.

Thank you!

What I was basically looking for was a list of things that I need for the CO2 setup. I keep reading about bits and pieces of stuff but not an entire list. And not an extensive list like 1 piece of 2" PVC pipe, but a list like (for a general tank setup) Heater, Filter, Lights, substrate, etc. And then a diagram showing the entire thing setup and how it is supposed to look.

From what I have gathered, I need:
3 Gal jugs
Tubing (a special type)?

I have read that soda bottles are best because of the construction and it is made for the pressure of bottled soda. Would Water jugs work or would I be better getting 2L soda bottles? If I do go with the 2L soda bottles, will I have 6 of them setup at the tank at all time? That seems pretty cluttered. Would it be better to just go with the pressurized CO2 in the pre-made unit considering the tank size?
It would be much better to go with pressurized in a tank of your size, or just about any size for that matter.

As far as bottles go, those hard plastic one gallon Poland spring bottles with the handles work very well.
I'm thinking that it may be the way to go too. Having 6 bottles around my tank is not exactly a desired situation. Especially since I have an open stand. I can't hide anything anywhere.
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