Where's Bill Nye when I need him?
Planted Tank Forums
Your Tanks Image Hosting *Tank Tracker * Plant Profiles Fish Profiles Planted Tank Guide Photo Gallery Articles

Go Back   The Planted Tank Forum > Specific Aspects of a Planted Tank > DIY


Reply
 
Thread Tools Display Modes
Old 12-29-2012, 06:36 PM   #1
dprais1
Planted Tank Enthusiast
 
PTrader: (13/100%)
Join Date: Sep 2012
Location: mt prospect
Posts: 907
Default

Where's Bill Nye when I need him?


I have a pop bottle for my DIY CO2. First couple of days I get crazy amount of little bubbles in my tank. Then it levels off and stays that way 24/7. If i jostle the bottle a little bit a get a 3-5 second 'burst'

BUT if I take the cap off the pop bottle for 10min or an hour then put the cap back on in a short while I have crazy bubbles again for several hours.

This morning, 8:30am, was 10 min off, now it's 1:30pm and I still have crazy bubbles.

Anyone know why or seen similar results?

If not anyone know where I can find Bill Nye?
dprais1 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 12-29-2012, 06:39 PM   #2
lipadj46
Planted Tank Enthusiast
 
lipadj46's Avatar
 
PTrader: (5/100%)
Join Date: Apr 2011
Location: NY
Posts: 939
Default

google yeast and aerobic respiration, no science guy needed.
lipadj46 is offline   Reply With Quote
Old 12-29-2012, 07:12 PM   #3
Geniusdudekiran
Prodigious Plant Pundit
 
Geniusdudekiran's Avatar
 
PTrader: (44/100%)
Join Date: Dec 2010
Location: Columbia, SC
Posts: 5,371
Default

I think that you can find him on some old VHS tapes in my closet from my days where I would sit, fascinated, in front of the non-flatscreen, non-HD TV chanting "Bill! Bill! Bill! Bill!"
__________________
"Simplicity is the ultimate sophistication." -- Steve Jobs
Geniusdudekiran is offline   Reply With Quote
Old 12-29-2012, 07:16 PM   #4
DarkCobra
Planted Tank Guru
 
DarkCobra's Avatar
 
PTrader: (5/100%)
Join Date: Jun 2004
Location: Baton Rouge, LA
Posts: 3,349
Default

Yep. If yeast are provided with oxygen, they can convert an equal amount of sugar into *four times* more CO2 (if I recall right), producing no alcohol.

The problem is that air is mostly nitrogen. All that inert nitrogen, which is insoluble in water, has to be purged out of the system. Which, depending on your diffusion scheme, creates bubbles that carry away much of your bonus CO2 uselessly to the top of the tank. Or fill a reactor until it burps out nitrogen and CO2.
DarkCobra is offline   Reply With Quote
Old 12-29-2012, 07:34 PM   #5
dprais1
Planted Tank Enthusiast
 
PTrader: (13/100%)
Join Date: Sep 2012
Location: mt prospect
Posts: 907
Default

--facepalm
dprais1 is offline   Reply With Quote
Old 12-29-2012, 09:32 PM   #6
flc
Algae Grower
 
PTrader: (0/0%)
Join Date: Sep 2012
Location: Portland, Oregon
Posts: 71
Default

Quote:
Originally Posted by DarkCobra View Post
Yep. If yeast are provided with oxygen, they can convert an equal amount of sugar into *four times* more CO2 (if I recall right), producing no alcohol.

The problem is that air is mostly nitrogen. All that inert nitrogen, which is insoluble in water, has to be purged out of the system. Which, depending on your diffusion scheme, creates bubbles that carry away much of your bonus CO2 uselessly to the top of the tank. Or fill a reactor until it burps out nitrogen and CO2.

And roughly 18x the energy yield from using the Embden Meyerhof Parnas pathway. If the fermentation is being done through the Entner Doudoroff pathway, CO2 production is roughly 1/6 the Krebs Cycle with 1/36th the energy yield. (Due to thermodynamic inefficiency in transmembrane energy transduction, the numbers aren't quite as clean as textbooks state)

Back to the OP's question:
The fizzing effect from shaking is because the solution is "saturated" in CO2 and the kinetic energy you're imparting to the system is just enough to push it over the energy threshold required for a shift in its equilibrium. In other words, you're making CO2 when you shake the bottle.

Unlike O2 (which interacts with water through dipole alignment), CO2 reacts directly with the water: CO2 + H2O --> H2CO3. After a certain amount of time, the reaction making carbonic acid (H2C03) slows until the concentrations of reactants and products reach equilibrium. At equilibrium, the reaction rate in the forward and reverse directions is balanced: CO2 + H2O <--> H2CO3

When you impart energy to the system (heating, shaking, gorgon death ray, etc), you shift that balance. As a result of the reaction being exothermic, the reaction goes faster in reverse than forward, so that the net reaction produces C02 until the relative concentrations reach a new equilibrium state and the rates go back to being in balance: H2C03 --> H2O + C02.

Edit: If you really want to go down the rabbit hole, here's a more complete explanation: http://www.newton.dep.anl.gov/askasc.../chem99661.htm

Last edited by flc; 12-31-2012 at 05:20 PM.. Reason: Added link
flc is offline   Reply With Quote
Old 12-30-2012, 02:15 AM   #7
DarkCobra
Planted Tank Guru
 
DarkCobra's Avatar
 
PTrader: (5/100%)
Join Date: Jun 2004
Location: Baton Rouge, LA
Posts: 3,349
Default

Wow. Well that puts my explanation to shame.

But you might be able to answer a question I have. If there *was* some way to keep the DIY mix aerobic, would it maintain a relatively stable CO2 production, same as we expect from our anaerobic mixes? Or would it instead rise exponentially until all sugar is converted?
DarkCobra is offline   Reply With Quote
Old 12-31-2012, 12:32 AM   #8
dmifflin
Algae Grower
 
PTrader: (0/0%)
Join Date: Mar 2012
Location: st tomas
Posts: 18
Default

im going to have to say well done with a side of b.s.. super entertaining btw .

essentially he is right.
dmifflin is offline   Reply With Quote
Old 12-31-2012, 12:46 AM   #9
dmifflin
Algae Grower
 
PTrader: (0/0%)
Join Date: Mar 2012
Location: st tomas
Posts: 18
Default

after further reading i retract my previous b.s. comment. flc you are the biggest nerd i know... praise the nerd.
dmifflin is offline   Reply With Quote
Old 12-31-2012, 07:34 PM   #10
Diana
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jan 2010
Location: Contra Costa CA
Posts: 7,708
Default

Yea to flc! Lets name him/her as the 'Bill Nye' of the Planted Tank!
Thank you very much! I have always wondered why stirring the bottle improved the yield, briefly.

ps: my adult son has (lets all sing) "Bill Nye the science guy... Bill! Bill! Bill!" as the ring tone on his phone.
Diana is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 07:22 AM.


Powered by vBulletin®
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright Planted Tank LLC 2012