# Co2



## pat3612 (Jan 29, 2008)

Hi I picked up a small co2 unit from pets mart Ive been reading about co2 put now Iam not sure I should use it, is there any chance this could wipe out my fish. thanks Pat


----------



## Darkblade48 (Jan 28, 2008)

Hi Pat, 

There are several types of CO2 units on the market, one is a pressurized system (i.e. compressed CO2) and another is a "biological" system that uses yeast to generate CO2; I suspect the one you purchased is the latter.

CO2 is used in planted tanks; plants require a source of carbon, and carbon dioxide is a method that this essential nutrient is supplied to them. 

Once you get the CO2 into the water, there are several ways to dissolve it into the water. 
1) Allow the bubbles to simply bubble up (not efficient)
2) Feed the tube into a filter input so that the impeller smashes up the bubbles
3) Using a diffuser of some sort (glass with ceramic disc, etc)
4) Using an in-line diffuser
5) Passive diffusion (i.e. with a bell diffuser, etc)

It is possible to cause death if you exceed a certain CO2 concentration in the water; with a yeast powered unit, this is possible, especially in smaller tanks.


----------



## dekstr (Oct 23, 2007)

You could overgas DIY yeast-based co2 in a small tank.

I killed all my pond snails in my 2.5 gallon with too much co2. Their shells eroded and they all died, floating to the surface.


----------



## Chris S (Dec 19, 2007)

As Darkblade put it, yes, you can kill your fishies!

I'm assuming you probably got the Nutrafin Natural Plant System one, which comes with a ladder to diffuse the bubbles. I ran two similar yeast ones on a 20g without any problems or hiccups, but in the end found that DIY c02 is often more trouble than it is worth.

I think it will be hard to pump too much c02 from one of those systems into the water, unless you are using it on like a 5g tank or something very small. The only other thing I have heard happening is a suction that pulls all the yeast mixture into the aquarium. Ugly, but not really that deadly (or so I hear).


----------



## pat3612 (Jan 29, 2008)

Yes it is a nutra fin one and my tank is a 20 gal since my plants are not dying maybe ill just give them ferts for now and see how it gos, is there anyway to measure the co2 in the water. Sorry just trying to grasp alot of information. Ahhh getting old things dont stick in the head like they use to short term memory loss. lol


----------



## Darkblade48 (Jan 28, 2008)

I think a good ballpark method of measuring CO2 is with a drop checker. (Shameless self plug) I made a DIY CO2 drop checker, you can check it out in the February POTM thread.

Another way to check the levels of CO2 in your tank would be to test the pH and kH of your water. Set aside a small sample and allow it to off-gas (i.e. any CO2 dissolved in the water will move back quickly into the atmosphere) for 24 hours. Then re-test the pH. There are several online calculators that can determine your CO2 levels in this manner as well.


----------



## pat3612 (Jan 29, 2008)

Thanks everyone for all your information.


----------



## Chris S (Dec 19, 2007)

If you are putting ferts in, keep in mind that Carbon is one of those... Missing one link usually leads to algae!

20g tank - with one of those nutrafin things it would take some serious effort to overdose your tank with co2. 

If you are still wary, you can try using Seachem's Flourish Excel to provide carbon to your plants by dosing.


----------



## pat3612 (Jan 29, 2008)

Chris Stewart said:


> If you are putting ferts in, keep in mind that Carbon is one of those... Missing one link usually leads to algae!
> 
> 20g tank - with one of those nutrafin things it would take some serious effort to overdose your tank with co2.
> 
> If you are still wary, you can try using Seachem's Flourish Excel to provide carbon to your plants by dosing.


Ok thanks Chris.


----------

