Tuesday, January 19, 2010


Huh?...I think a search on the term 'DIY CO2' will result in tons of site on info of how to build one. Don't believe me? Try it...you will get lots of infos from designs, to recipes......

Kinda funny to see so many sites about DIY CO2, and yet I publish my own copy here...haha.....WHY? Because, today, I happen to see the DIY CO2 diagram on my sister desktop which I draw few month ago for a friend....so, it just spark like that, and here goes my DIY CO2...enjoy :D

Here's the diagram which I draw for a friend few months back...okay, ignore the Copyright, this one I edited today :D

Okay...here's what you need...
- 2 plastic bottles (water bottle, soda bottle, etc...your choice)...make sure it comes with their respective cap :D
- 1 extra bottle cap of the same bottle type
- some air tube
- a check valve
- a diffuser

Tools you might need:
- something you can use to make holes on the cap of the bottle, such as drill, nail, etc....something you are comfortable working with :D
- pliers (you may not need this if you have strong fingers :D...hehehe)

- a pinch of yeast (I use only baker's yeast)
- 2 to 3 table spoon of sugar
- water
- baking soda...(some people suggest, but personally I haven't tested with baking soda)

So that's about it...so lets start building your CO2 factory :D

Step 1. You will want to mark bottle 1 and bottle 2, so you don't get mixed up later on.

Step 2. Make one hole on the cap of bottle 1 and 2 hole on the cap of bottle 2. Make sure the size of the hole is slightly smaller than the air tube. As this will create a snug fit and act as a seal when the tube is insert into the hole.

Step 3. Insert the airtube into the holes. For easy working...cut the end of the air tube diagonally. Now with the pointed air tube, insert the tube from the top of the cap. If you have strong fingers, you can pull the pointed end of the tube, or else use a pliers to do it :D

Step 4. Build your DIY CO2 factory as in the diagram above. Make sure the check valve is in the correct direction, or else you won't get any CO2 into your tank.

Step 5: Mixing the ingredients...first make sugar water and fill it into bottle 1 till half full. Next add 1 pinch of yeast. Cap it with the extra bottle cap, and shake the solution vigorously for few moments. On the other hand, bottle 2 can be fill with plain water 2/3 or 3/4 full.

* the measurement is not quite certain, but rather a gut feeling...the more yeast, the faster the solution will finish...lesser yeast, more sugar, and the solution will last longer.

Step 6:
Assemble all the parts together, this is how it looks like in real...

Bottle 1 is the one with the white cap, Bottle 2 with the blue cap

Everything similar as in the diagram I draw...accept for the stop valve (doesn't make much different with it)

View from another angle

Some explanation...
In some sites, you might see some design with a single bottle, which is bottle 1 direct to the diffuser, with check valve in between. Now you might be wondering why I use a second bottle...the reason is simply to serve as a filter. In bottle 1, the bi-product of yeast and sugar are CO2 and alcohol. So that's where the second bottle comes in, to filter the alcohol and prevent it from entering your tank :D

I had experienced before using only a single bottle, my tank smell alcohol....LOLz!!! and my fishes got poisoned by it. So for safety purposes, as a precaution, use a second bottle :D

Now...if you may ask, what bottle size I used, those in the pic are 500ml mineral water bottle. Instead of discarding it into the bin, I recycled it for the DIY CO2 :D

Well any bottle can serve for this purpose. I guess the larger the bottle, the more amount of ingredient you can add, and that might last a little longer :)....anyway my setup last for about 2 weeks....by week 2, the CO2 bubbles beginning to slow down.

So...I guess that's about it on DIY CO2....so enjoy making yours :D

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