# Another (but very successful) DIY CO2 setup



## MPred

Hi Everyone. Just wanted to report on my DIY CO2 setup that I have had a lot of luck with










Idea: Make a cheap/free CO2 system for under $10

Materials: 
Q=1 710ml water bottle
Q=1 500ml water bottle
Q=2 feet of airline
Q=1 airline tee
Q=1 check valve
Q=1 lime wood air stone or Fluval ceramic CO2 Diffuser
Q=1 Fluval 20 CO2 Diffuser (only one half of it, you can put both parts in but it takes a lot of room, and limits the effectiveness of the lime wood air stone)

I'll let you figure out the method... You're pretty smart 

Reasoning:
THE TEE: It has a tied off section of airline so that if pressure builds up it pops off rather than blows up the bottle. Unlikely, but since I sleep 6 feet away from it... necessary
THE SECOND BOTTLE: I use it as a bubble counter and it filters the CO2 from the yeast bottle which contains trace amounts of the yeast formula in which I don't want in my tank... necessary
THE CHECK VALVE: so the tanks water doesn't siphon into my bottles... not necessary
THE DIFFUSING SYSTEM: OK, so the Fluval diffuser acts on the idea that a trapped volume of CO2 underwater will dissipate into the water. It works but its slow and you end up with a lot of loss from a DIY setup due to the inability to shut off flow. SO with the lime wood air stone (which is also an acceptable way to mix CO2 into the water) the CO2 leaves the generator, bubbles through the lime wood, and the CO2 not absorbed into the water is then caught and saved for later in the Fluval diffuser










Mixture:
1 cup sugar
1 tsp baking soda
1/2 tsp yeast (I use bakers yeast but I will be trying brewers yeast next batch due to its ability to survive the alcohol that builds up in the generator)

KEY POINT: The yeast is as living as the rest of your tanks inhabitants... mixing/starting you generator is essentially birthing the yeast which will "breath out" the CO2 you want. If you mess up at this point... start again... it wont work as well as if you do this properly

Take a cap full or two of lukewarm bottled/dechlorinated/aquarium water, a pinch of sugar and the yeast and mix together until the yeast "dissolves"
and let it sit for 10 minutes
THIS IS GIVING LIFE TO THE YEAST

Fill the 710ml bottle 2/3 full of lukewarm bottled/dechlorinated/aquarium water and add the sugar

After the 10 minutes is up add you yeast to the sugar water.

NOTE: The yeast is the "creature" and the sugar water is the "food"

Any questions or anything to add, feel free to comment.
No hating, these are just my experiences... I don't know anything at all
Good luck
-Mark


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## MPred

*UPDATE*
Method:








1. Clean everything in warm water. LOL dont use soap 
2. Attach your lime wood diffuser (or ceramic CO2 diffuser) to the bottom of the Fluval Bell Diffuser with a short piece of airline and then connect the check valve with a short piece of airline to the top of the bell. (make sure the check valve is going the right way)








3. CAREFULLY drill one hole into the 710ml cap and two holes into the 500ml cap (make sure the holes you drill are smaller than the airline to ensure a tight fit without leaks








4. Add the airline from the 710 cap to the 500 cap, pulling extra line into the 500 so that the CO2 ends up bubbling into the 500 at the bottom.








5. Add the second airline in the 500 cap that then hooks up to the previously assembled diffuser system.


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## marko

Very nice I would like to use c02 but my tank mates like to eat plants just wondering how often do you have to change the yeast daily?


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## MPred

It'll last about 1.5-2 weeks at 10 BPM, fairly long lasting setup


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## pisces

thks for share! i always worry very hard to do it!
i will try , if any question may ask u , thks!
just woundering if i get up 20 G , so do i need choose the bigger bottom and fill little more the CO2 and how many do i need ? thks!!!


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## MPred

pisces said:


> thks for share! i always worry very hard to do it!
> i will try , if any question may ask u , thks!
> just woundering if i get up 20 G , so do i need choose the bigger bottom and fill little more the CO2 and how many do i need ? thks!!!


sounds good!
hmmm... i've only got experience with the little one, try minimum of two.


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