# CO2 tablets?



## AquaNekoMobile (Feb 26, 2010)

http://cgi.ebay.com/CO2-Tablet-Live...tem&pt=LH_DefaultDomain_0&hash=item3a55a3a9cf

Was just checking out Bumleboo's shrimpie link and got curious on the ebay thing and saw the something else with co2 tablets which got me curoius. CO2 tablets? Anyone use something like that or similar to it?

I don't htink it'll harm plants but fish I think there is a possiblity depending how much co2 effects the pH as far as I understand it. I could be wrong on that understanding but then again that's why I'm posting here to learn on that.


----------



## Darkblade48 (Jan 28, 2008)

These kinds of products seem to always appear every so often; they are like a seasonal cold.

Unfortunately, these tables cannot provide a sufficient, steady source of CO2 for a planted tank. You would get bursts of CO2, depending on how fast the tablet dissolves, how efficient your diffusion rate is, etc.

I recall that Amano also used to try using CO2 tablets (namely Alka seltzer tablets) in order to raise the CO2 content, but it usually failed.

Finally, there is no problem with the pH drops that are associated wtih injecting CO2. However, if CO2 levels become too high, it will prevent the binding of oxygen within living organisms (at least those that use a heme type blood), essentially suffocating them.


----------



## AquaNekoMobile (Feb 26, 2010)

So if co2 is high would it mean you should add more air stones and bump up the o2 in the tank?


----------



## Darkblade48 (Jan 28, 2008)

Air stones do not increase the level of oxygen directly.

In addition, adding an airstone would mean that the CO2 that you worked hard to get into the water column in the first place will diffuse away.


----------



## KhuliLoachFan (Mar 8, 2008)

A 2L coke-bottle and a $0.50 packet of yeast, and $0.25 worth of sugar, and air-line tubing you already have, plus some kind of DIY-diffuser and you're in business. Forget the Co2-pills and so on. 


W


----------



## AquaNeko (Jul 26, 2009)

KhuliLoachFan said:


> A 2L coke-bottle and a $0.50 packet of yeast, and $0.25 worth of sugar, and air-line tubing you already have, plus some kind of DIY-diffuser and you're in business. Forget the Co2-pills and so on.
> 
> W


How long does a 2L bottle co2 setup last roughly in a 10gal? Say on the most conservative air out setting with little bubbles?


----------



## Darkblade48 (Jan 28, 2008)

AquaNeko said:


> How long does a 2L bottle co2 setup last roughly in a 10gal? Say on the most conservative air out setting with little bubbles?


What do you mean by "conservative air out setting with little bubbles"? One disadvantage with DIY CO2 it that you cannot really control it at all.

However, DI CO2 will last, on average, about 2 weeks. You may be able to get 3 weeks if everything is optimal, etc.


----------



## AquaNeko (Jul 26, 2009)

Darkblade48 said:


> What do you mean by "conservative air out setting with little bubbles"? One disadvantage with DIY CO2 it that you cannot really control it at all.
> 
> However, DI CO2 will last, on average, about 2 weeks. You may be able to get 3 weeks if everything is optimal, etc.


Meaning if I used one of those single air line regulators to bleed the co2 into the tank so I can control how much co2 enters the tank.

I read about a 2cup sugar to 1/2 teaspoon yeast mixture will last 2-3 weeks from this site http://www.plantedtank.net/articles/DIY-Yeast-CO2/7/


----------



## Firerox (Apr 26, 2010)

Do NOT use an airline regulator with DIY Co2. The pressure on the bottle-end of the airline will build up and eventually explode.


----------



## BettaBeats (Jan 14, 2010)

Firerox said:


> Do NOT use an airline regulator with DIY Co2. The pressure on the bottle-end of the airline will build up and eventually explode.


It's hard to say.. if you were gentle and not generous on the valve you could maybe control the pressure. Sometimes DIY CO2 in a 10gal is too much! Like 2-3 bubbles a second, and that is potentially dangerous on such a small tank.. it can maintain this bubbles/second rate for 2-4 days or longer before it slows down.. resulting in prolonged lack of oxygen and then asphyxiation of the fauna.

I'd like to try a valve, but I'm worried about the building pressure and explosion. If you could make a blow-off valve, that would be pretty cool.


----------



## AquaNekoMobile (Feb 26, 2010)

Has there been any documented proof that a single DIY 2L set has exploded?

I know form mythbusters IIRC the 2L bottle has a max psi of ~90-100psi before structual failure resulting in the bottle blowing up. They tested this in thief 2L bottle cluster lift off of a human episode.

Now I'm not sure what psi can be generated by 2cups of sugar and 1teaspoon of yeast as I do not have a psi pressure dial setup on top of the 2L setup. Perhaps some chemists can weigh in on this?

Somehow I am feeling like the above mixture ratios would not build enough pressure to reach structural failure as there is slow pressure leaking out into a fish tank. Now if that was bottled up pressure with not pressure bleed off I would think differently. Granted I have not done DIY co2 before so those are just assumptions based on gut felling.


----------



## Darkblade48 (Jan 28, 2008)

A DIY 2L bottle can explode if the output end is clogged. Adding a valve to control the valve can be potentially disastrous, if the valve allows too much pressure to build up, etc.

There was a recent thread on TPT that detailed an exploding DIY CO2 bottle.


----------



## AquaNekoMobile (Feb 26, 2010)

Darkblade48 said:


> A DIY 2L bottle can explode if the output end is clogged. Adding a valve to control the valve can be potentially disastrous, if the valve allows too much pressure to build up, etc.
> 
> There was a recent thread on TPT that detailed an exploding DIY CO2 bottle.


I'm thinking if I use a T splitter then I can two air stones in the tank so should for some reason one stone was clogged I have a back up air outlet. I was thinking of putting the air tube and stones down a sponge filter so it do double duty at the same time or something like that in combo with my AC20.

Would the T idea work?


----------



## AquaNekoMobile (Feb 26, 2010)

Darkblade48 said:


> A DIY 2L bottle can explode if the output end is clogged. Adding a valve to control the valve can be potentially disastrous, if the valve allows too much pressure to build up, etc.
> 
> There was a recent thread on TPT that detailed an exploding DIY CO2 bottle.


How much PSI is generated by the 2cup and 1/2 teaspoon of yeast mixture? Is there a formula for calculating that?


----------

