Many hobbyists like to have natural plants in their aquariums. Depending on factors such as lighting and the types of plants you keep, you may need to add CO2 to your system. However, buying a pressurized setup can be a bit costly. In comes DIY (Do-It-Yourself). Even then, some people think that even this method is cumbersome. Well, here we are going to go from start to finish just to show how simple it really is.

Step I: Making the medium (a.k.a Jell-O)
............. Ingredients: 1 pk. Regular 6oz Jell-O. Flavor Optional.
.............................. 2 ½ cups boiling water
.............................. 2 cups pure cane sugar


............. 1) In a large saucepan, fill with water and bring to a rolling boil.
............. 2) Empty (1) 6oz package of Jell-O in a large mixing bowl.
............. 3) When water is boiling, carefully measure out 2 ½ cups.
.............................. a. CAUTION: Contents will be very hot. Be Careful.
............. 4) Pour water in bowl with Jell-O and mix thoroughly until well dissolved.
............. 5) Pour in sugar and thoroughly mix again until well dissolved.
............. 6) Once everything has been dissolved, pour contents in a flat Tupperware container.

............. 7) Cover and place in refrigerator.

Step II: Making the Reactor
............. While the Jell-O is setting up, let’s make the reactor vessels.

............. Materials: 1 64oz Juice bottle (Ocean Spray seems to be best)
........................... 1 1pt bottled water bottle
........................... 4’ CO2 tubing
........................... GE Silicone I caulk (optional)
............. Tools:..... Cordless drill w/ bits
........................... Scissors
........................... Case Knife
........................... Needle Nose Pliers
........................... Toothpick

............. 1) Start by thoroughly cleaning both bottles with hot water.
............. 2) Remove lids. Drill a 3/16 hole directly in the center of the juice bottle lid. Drill two holes in the smaller water bottle lid.

............. * NOTE * For best results, start with a small drill bit to create a pilot hole. Then using other bits, work your way up to 3/16. The 3/16 size is a fraction smaller than the diameter of the tubing and will provide for a tight fit.

............. 3) Using the case knife, carefully trim any shavings left by the drill bit.
............. 4) Measure about 2’ of tubing.
............. 5) Using scissors cut one end of the tube at an angle.


............. 6) Push the angled end through the top of the cap.
............. 7) Using the pliers, grab the end and carefully pull the tubing the rest of the way through the cap.

............. 8) Cut off the angled end to make a flat cut.
............. 9) Slowly pull tubing out of cap until about ¼” remains in the cap.
............. 10) Repeat steps 5-8 with the opposite end of the tubing into one hole of the water bottle cap.
............. 11) Test fit tubing in water bottle and adjust length if needed. There should be a bend in the tubing.

............. 12) Using the remaining length of tubing, repeat steps 5-9 using the second hole on the water bottle cap.

............. 13) Caulk around all three pieces of tubing on the inside of the caps using GE Silicone I caulk only. This is an optional step as the seal around the tubing will be sufficient with the 3/16” hole depending on how you diffuse the gas. I didn’t do this at first until I switched to a glass diffuser, which resulted in needing higher pressure. In one setup, I discovered a leak in the separator bottle so I added the silicone.
............. 14) Use the toothpick to spread the caulk completely around the tubing to ensure the entire area is covered.

............. 15) Set caps aside and let silicone cure at least 24hrs.

Step III: Time to make gas
............. Now that our Jell-O has set and our reactor vessels have been made, it is time to start making gas… CO2.
............. Ingredients: 1 tsp Bakers or Brewers Yeast divided
.............................. ¾ tsp for initial setup
.............................. ¼ tsp to add later
.............................. ¼ tsp. Sugar
.............................. ¼ cup hot water
.............................. ¼ tsp. Baking soda
.............................. Air stone (diffuser)
.............................. * NOTE * use a limewood airstone or glass diffuser for best results

............. 1) Activate the yeast. In ¼ hot water, dissolve ¼ tsp sugar. Stir thoroughly.
............. 2) While water is still spinning from step 1 (tornado effect as I like to call it), carefully pour in ¾ tsp of yeast. This will help in prevent clumping.

............. “snow globe” effect shows the yeast activating:

............. 3) While this is activating (appox. 15 minutes), cut Jell-O in small cubes. The small cubes allow for more surface action for the yeast.
............. 4) Add the cubes to the large bottle.

............. 5) After yeast has activated (again allow approx. 15 minutes), add 2 cups hot water to Jell-O bottle.
............. 6) Pour yeast mixture into bottle.

............. 7) Add ¼ tsp Baking Soda.
............. 8) Using hot water, fill bottle until you have approx. 2” free space from the lid.
............. 9) Add remaining ¼ tsp yeast.
............. 10) Fill seperator bottle with water about 3/4 full. Water should be over the end of the curved tubing. This will enable you to see and count the bubbles.
............. 11) Cap both bottles tightly. Remember to allow for a “curve” in the separator bottle.

............. 12) Within hours, you will start to see generation of CO2.


That’s all it takes. Now go grow beautiful and healthy plants.

******************
* EDIT *

I have since changed a couple things on this original design basically due to the pressure that builds up.

1) Replace the water/soda bottle that is used as the gas seperator bottle with a 20oz Gatorade bottle. These bottles provide a much tighter seal.

2) Caulk both top and bottom of the caps around the CO2 tubing.

how long does this reaction last for?

__________________
50 g tank
50g sump
5 angels
1 diamond tetras
5 ?? tertas
4 flooresent 4" 2 working
1 150W MH
DIY Co2 (yeast)
DIY Co2 reactor to come having troubnle finding parts
Winnipeg MB

i must have missed something.
whats the jello for?
besides the jello, it looks like every other DIY Co2 set up ive ever seen. so why the jello?

__________________
why buy, when you can DIY

The Jell-O holds in the sugar. As it slowly disolves, it releases the sugar to the yeast. Makes it last longer.

This sounds cool, I'm going to save this and read it over when I get some more time! Thanks.

* EDIT *

Added an additional step at the end of Section III (Thanks trouble93). It was not previously mentioned to fill the gas seperator bottle with water. That is now Step 10 in Section III.

James,

In your original recipe:
2) Empty (1) 8oz package of Jell-O in a large mixing bowl. - this is not a typo right? All I see in our Supermarket is 0.3 Oz packages ...

Thanks,
Aram

how much longer are we talking about?
does the slower dissolving sugar decrease the amount of Co2 produced?

__________________
why buy, when you can DIY

Do you get a white slimy substance growing on the diffuser with this DIY CO2 method?

no..that is what the seperator bottle is used for.

No this is not a typo. There are usually two box sizes a small and a large.

I've had bottles last well over two months. No decrease in the production.

Is this setup made for any certain size of aquarium? Is it possible to put to much CO2 into your system

If you use the RIGHT drill bit you do not have to silicone the hoses into the caps.

Ill get pics of mine later, I am running a 4 bottle system with 1 accumulator and two powerheads for reaction.

I use brewers yeast, it lasts longer then bakers yeast or Jell-o, same principal, add a smidge of brown sugar to the mix and you got a 2 liter that lasts for atleast 20 days.

Winemakers or Brewers yeasts are the ones to use, active dry baking yeast consumes too quickly, brewers yeast lasts longer mainly due to the brewing process lasting longer then baking breads.

This is true to some extent. It depends on your diffusion method. I originally started with smaller drill bits and using limewood diffusers. I have since switched to ceramic glass diffusers. The pressure was too much for the bottle which resulted in leaking from the cap which is why I used Silicone for the tubing. I can now effectively use these diffusers for the DIY setup.

The type of yeast does make a difference such as chamagne yeast will yeild the best results. As for my set ups, I go over a month prior to having to recharge them. Other factors come in to play as well such as room temp.

Definately if you can, get brewers yeast. They are more tolerant of the higher alcohol levels thus lasting longer.

Also, one bottle of DIY CO2 is generally used for up to 20g tanks.

yep, add some juice concentrate instead of jello, when the Co2 is done, bottoms up! LOL

Aquarist's vino.

Yes but having sustained levels of Co2 and consistency are harder to achieve on large tanks, 4 bottles keeps me going fine for about 20-25 days, same size bottle for accumulator with about 3" of water in it to makes the muck sink and easier to clean out.

The brown sugar does help, it gives it a nice kick for about 10-14 days straight. 1tblspn per bottle. I think its a richer sugar and more of it being its not just white sugar, better chemical make-up I think.

__________________
20 Gallon Planted Tank
3.45wpg, Eco-Complete substrate, 6500k CFL, Pressurized CO2, Flourish Excel, Flourish Trace, and Flourish
Platys, Oto Cats, Bumble Bee Shrimp, Crystal Red Shrimp and Red Cherry Shrimp
Limnophila Aromatica
Stargrass
Red Wendtii Cryptocoryne
Dwarf Hair Grass
Baby Tears (HM)
Dwarf Baby Tears (HC)
Red Lotus Tiger Lily
Red Lotus Dwarf Lily
Java Moss
Christmas Moss

the jello slow releases the yeasts food.
how long has it been "cooked" up for the Co2 mix that is?

I used jello twice, ones a failure 2nd benifit of user error. I could never get it to be consistent. I use my method because thats what works and havnt had a problem if anything it produces too much Co2 then I have to turn it down with the venturi valve. the first 3 days I dont get bubbles I get a stream of Co2 from the bottles then it goes into a reserve tank where pressure is always built up from the brew.

I will take pics asap i gotta get ready to take my kids to their grandmas for the week 8hrs round trip today. I doubt I will get to it.

I am having an issue with my setup I did everything to the above directions and my seperator bottle is creating bubbles (one about every six to ten seconds) It has been going for about 24 hrs now but there isn't any sign of the water level in the air line going down over an 1.5" to even suggest that pressure is building... The seperator bottle is not leaking I siliconed the cap to the bottle and the hoses to the cap. Any suggestions?

Sounds as if you have a leak somewhere. What kind of bottles are you using? I ask because some types of threaded lids will be prone to leaking. Make sure all is tight.

What are you using as your diffuser? Are you using a regular airstone?