# World's most advanced DIY CO2



## ncutler (Mar 5, 2009)

Yes, I'm going for the ultimate title with this project!

Before I get pressurized CO2, I want to master DIY first, in order to understand it as best that I can.

My challenge has been to create consistent CO2 that won't cause too much stress on the fish. I've gone from the Nutrafin bubble ladder kit to using multiple bottles, but they all seem to create quite inconsistent CO2 that at oner point caused my Ph to drop from 7.4 to 6.4 in under 2 hours, causing my ick outburst (at least that's what I believe caused it). This weekend I bought a needle valve at IPZ (and had a great hour long chat with Brad). I must say, it definately works without much back pressure.

But now my challenge is to find ways of being able to relieve the back pressure if it gains too much. So this is my current contraption:










Notice the 3 way brass valve. This will hopefully be set to release once a set amount of back pressure builds up. Hopefully the needle valve will work perfectly from a slight back pressure (so far so good) such that the valve will only release at a back pressure threshold.

The bottle on the right has 2 cups of gelatined sugar along with 20% distillering yeast. The top is water + 1 cup of sugar. The theory is that the yeast will only have access to the sugar available at the top of the gelatin and will eat the gelatin over time.

As I've discovered, multiple bottles should only be used if you want to stagger the bottles - change one while the other is still good. The check valves are required to make sure the CO2 gas doesn't get shared between all bottles.

I have one further step I am going to try: adding a smaller, empty bottle to the chain, with a closed valve. This should allow me to open the valve only when backpressure is high, thus pushing some CO2 into the empty bottle, once pressurized, I'll have a backup supply if ever I find my CO2 pressure running low.









bubble counter ontop, Red Sea needle valve below.

All this to try to recreate the consistency that pressurized CO2 easily does. It is a good challenge!

PS: My boss thinks I'm the only one in North America who finds this interesting!


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## bartoli (May 8, 2006)

ncutler said:


> Before I get pressurized CO2, I want to master DIY first, in order to understand it as best that I can.
> 
> My challenge has been to create consistent CO2 that won't cause too much stress on the fish.


Since you will eventually go to pressurized CO2, nothing beats having a pH-based CO2 controller in maintaining a consistent CO2 as long as your KH is stable.


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## Diana K (Dec 20, 2007)

"PS: My boss thinks I'm the only one in North America who finds this interesting"

You are not the only one. Don't tell your boss, but he/she is wrong on this point. 

I am aiming for more consistent supply by running several bottles at one time, and changing them out weekly. 
I see the problem of having them cross connected, and why you are putting in one way valves. I hope they hold up for you.


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## Zapins (Jul 28, 2004)

Interesting. Maybe you could use a syringe to act as a pressure release valve. Just make another hole in the syringe so you can add a tube from the CO2 bottle. This way if the pressure gets too high somewhere in the line it will expand the syringe and eventually pop out the thumb injecting part. This should protect your system from exploding if the syringe can handle the normal operating pressure. You might need to try a few different sized syringes to get the right resistance.


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## intothenew (Aug 1, 2008)

There are two practical ways to buffer a pressurized system.

1. Add a pressure release valve to the system. This would be set to some pre defined point and excess would be let to atmosphere when the system reaches that point. You therefore waist anytime that you are over productive. I can't tell exactly from the pic, but that looks like a simple needle valve. Is it a pressure relieve valve?

2. Add a large volume tank to the system. In this method, any increase in the amount of substance causes less of an increase in pressure. You obviously do not lose anything to atmosphere.


There is a number of other methods, but I don't think they would be practical.


1. Use a deformable bladder(balloon) attached to the system. I say bladder because I don't think that you could find a balloon at the five and dime that is non-permeable to co2. But, assuming you could, the change in volume of the bladder would buffer pressure increases.

2. Use a temperature control circuit. Decreasing the temperature will drop the pressure.

3. Only hire yeast that belong to the Union, they will make sure that things run steady.



The Golden Rule: PV=nRT


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## Diana K (Dec 20, 2007)

"3. Only hire yeast that belong to the Union, they will make sure that things run steady."

Are these yeasts willing to work for just sugar, or do they demand health benefits, retirement benefits, paid holidays, weekends off and other perks?

It has been a while since I looked into the variations of DIY. 
How is the gelatinized system coming along? Is the CO2 supply more steady? Or does it work over a longer time?


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## intothenew (Aug 1, 2008)

Diana K said:


> do they demand health benefits, retirement benefits, paid holidays, weekends off and other perks?


Yes, and you left out the most cost prohibitive, death benefits for millions.


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## Diana K (Dec 20, 2007)

That does it. 
I am only hiring non-union yeasts. Then I can dump the dead ones without costly company paid funerals, and widows/widowers pensions.


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## essabee (Oct 11, 2006)

Been there. Done that. View/browse - http://www.aquaticplantcentral.com/forumapc/diy-aquarium-projects/45030-co2-madhatter-s-diy.html. I don't think anyone has been touched by more madness to make a bigger one - so this would also be the largest. 

Now using pressurised CO2.


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## Zabman14u (Jun 20, 2009)

http://www.mcmaster.com/#pop-safety-valves/=49g2si

is a simple pressure relief valve that you can use. i use one in a small bleeder tank i made to set the tire bleeders for a race car. simply attach it to the top of probably the canister and you should be set. i would order one that is just a little more than what you need to get the CO2 to the bottom of your tank. no point in pressurizing it more than you need to. jmo


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## addicted2reefin (Oct 2, 2009)

a good pressure relief valve that i did back in the day and cost about 20 cents. If you can find a small ballon, put it on a T, and as pressure builds up the balloon pops off, simmiliar to the syringe.


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## ncutler (Mar 5, 2009)

I've since added a 950 ml bottle to the 3 way valve. It functions as a resevoir that increases the total amount of co2 the system can store. I've not had to worry about too much pressure, I've checked daily and it appears as long as co2 is being let into the aquarium, it doesn't build up to dangerous levels (I can always depress the bottle a bit).

I've also noticed that the side benefit of having a resevoir means that using the type of check valves I use (spring loaded), as soon as I undo one bottle, the back pressure closes the check valve tightly, allowing me to change a bottle without it stopping the flow.


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