# Consistent 2-3 bps with "pressurized" DIY CO2



## Rex Grigg (Dec 10, 2002)

Damn for $40 (adding in shipping) you could have gotten a much better needle valve. 

Or you could have gotten parts and split your pressurized CO2.


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## Green Leaf Aquariums (Feb 26, 2007)

UnusualSuspect said:


> _I mentioned this in another thread recently, thought it might be of interest._
> 
> I decided awhile back to add DIY CO2 to my 29 gal tank and quit using Excel. (I already had pressurized CO2 on my 90 gal.)
> 
> ...



Good job! DIY co2 is livin! Thanks for sharing Mike.


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## UnusualSuspect (May 25, 2007)

Rex Grigg said:


> Damn for $40 (adding in shipping) you could have gotten a much better needle valve.
> 
> Or you could have gotten parts and split your pressurized CO2.


Built from parts on hand. I had these things sitting in a junk box, left over from a year ago from my first foray into CO2, when I was truly a lost and desperate aquarist.  

When I started with CO2, I was pretty much buying whatever parts the LFS could order from their catalog. They didn't have any other customers doing CO2 at the time, so they were learning along with me. (FWIW, I recommended your regulators to them, gave them the literature that you sent with my Rex-ulator.)

Yes, I considered splitting the pressurized CO2, but (a) it's a long-ish run between the two tanks, and (b) this gave me a project to work on for awhile.

I'll probably replace this tank soon - I'm thinking a 36 bow - and may go pressurized at that time. If so, I'll be in touch for parts.

Mike


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## swylie (May 10, 2007)

UnusualSuspect said:


> So I sez to myself ... self, we _need a way to even out the gas delivery_ here. I had some pieces-parts on hand from when I first started using pressurized CO2 on the big tank, so I rummaged around. I found an old needle valve, bubble counter and reactor. I picked up a handful of cheapo check valves at the LFS and got to work.


I once thought about doing something like this but it occurred to me that it could explode so I never went any farther. As you've demonstrated, if you do it right it won't explode. I guess it's a balance between the amount of yeast you add and the bubble rate you're using. It occurs to me that there might be some negative feedback built into the system though, which is a good thing, and would reduce the risk of explosion. When the pressure builds up in the bottle the water is more acidic from more dissolved CO2. The acidic water might slow down the yeast and diminish the additional production of CO2. Since DIY CO2 _can_ explode this negative feedback can't be enough to completely stop the yeast, but it might slow it down a bunch. I don't know. I suppose I could answer my question by sealing off a DIY CO2 bottle with a pressure gauge attached and monitoring the pressure over time. If the pressure increase is close to linear then the added pressure and acidity doesn't slow the yeast much. If it's a curve, then there's significant negative feedback.

I have a feeling that your setup won't work for many people because it requires more monitoring and a more delicate balance than regular DIY CO2. That said, I think it's awesome that you've got this working for you. Oh, one more thing. Keep in mind that your needle valve is a flow regulator, not a pressure regulator, and that the flow through it will vary somewhat with the pressure across it. I guess this is another built in safety feature, since your valve will flow more CO2 at higher pressures.

Anyway, congrats on showing that it can work.


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## UnusualSuspect (May 25, 2007)

swylie said:


> Oh, one more thing. Keep in mind that your needle valve is a flow regulator, not a pressure regulator, and that the flow through it will vary somewhat with the pressure across it.


Yep, gotta tweak the valve a little thru the week as pressure in the bottles decreases. Not much, though.

When I replaced one of my generator bottles this morning, the whole system de-pressurized as a result of a cheapo check valve not working properly. There's a drawback to doing things on the cheap.

Thanks,
Mike


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## jaidexl (Sep 18, 2006)

Glad to see I was understanding you properly in the other thread, nice diagram. 

Easy solution to fear of explosion> place the bottles in a covered tupperware container with holes drilled for tubing. Or inside a large plush animal so you're tank would be fed CO2 from a huge fuzzy teddybear with a needle valve sticking out of his head. :tongue: :eek5:


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## swylie (May 10, 2007)

jaidexl said:


> Glad to see I was understanding you properly in the other thread, nice diagram.
> 
> Easy solution to fear of explosion> place the bottles in a covered tupperware container with holes drilled for tubing. Or inside a large plush animal so you're tank would be fed CO2 from a huge fuzzy teddybear with a needle valve sticking out of his head. :tongue: :eek5:


Your ideas are intriguing to me and I wish to subscribe to your newsletter. :icon_lol:


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## tropicalfish (Mar 29, 2007)

jaidexl said:


> Glad to see I was understanding you properly in the other thread, nice diagram.
> 
> Easy solution to fear of explosion> place the bottles in a covered tupperware container with holes drilled for tubing. Or inside a large plush animal so you're tank would be fed CO2 from a huge fuzzy teddybear with a needle valve sticking out of his head. :tongue: :eek5:


_"Mommy! My teddy bear is wet and stinky!"_
_"Go ask your dad..._


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## jaidexl (Sep 18, 2006)

Bwahahahaaa! 


There's a huge stuffed monkey sitting here that my fiance wants to get rid of, I think I might blow that sucker up with a yeast bomb. :icon_evil


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## UnusualSuspect (May 25, 2007)

Update: I have _not_ added any stuffed monkeys to the setup.  

Two weeks ago, the tank magically morphed from a 29gal with 65 watts to a 36 bow with 130 watts. I used Black Fluorite. Jeez I love this tank!

Anyway, about the CO2 - I switched the gas separator/gas storage bottle from a 20oz to a 1 liter, and it seems to be about the perfect size. For my yeast recipe, I cut back to 1/2 tsp yeast.

This thing has gotten _*really*_ reliable, I haven't had to tweak the needle valve in about three weeks now, and I'm not swirling the bottles, either. Swap out a generator bottle each week at water change time, and it just stays pegged in the 2-3bps range all week. My drop checker stays solid green at all times.

I (again) considered splitting the pressurized CO2 from my 90 gal, but this thing has settled into a groove and I don't really see the need. 

Hard to believe, but DIY CO2 is supplying all the gas I need in a heavily-planted hi-tech 36 bow with 3.6 wpg.

Regards,
Mike


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