Hagen co2 system

[aqua_chem]

CO2 is an acid and that make the kh to go down.

When you stop, the kh stop going down but wont be back up alone!

KH and pH are related.

KH increases as pH decreases, not the other way around. Not by much, but it does.

 

[MonsterfishGuy]

The kH doesn't change with co2... the pH does. that's how you can determine the co2 concentration by comparing the pH and kH. Normally, they do correspond to each other, until injecting co2 comes in to play.

I dont want to start a fight, so its just what i think happen in the water...

The chemistry behind KH is quite complex, so I will not go into too much detail, however in the most simple terms I can think of; is adding these carbonate (or bi-carbonate) buffers will raise pH to a point of stability and the continued use of certain carbonate buffer “mixes” may raise pH even more (which is why a KH of 50 ppm is all you would want with your discus, while a KH of 150 plus is recommended for African Cichlids or Marine Fish).

The rise in pH is related to the ratio of H+ to OH- ions. The CO3-- and HCO3- (KH) will react with the H+ and eliminate it. This reaction will cause more H20 to break up into H+ and OH- ions as H2O<->H+ + OH-. Because some OH- ions were already present, this shifts the ratio thereby raising pH and making the water base (alkaline).

With the same idea, the H2Co3+ (Diffused CO2) will react with the OH- ions. This reaction will cause more H20 to break up into H+ and OH- ions. Because some H+ where already present, this shifts the ratio thereby decresing pH and making the water acid!!

Thats it!

 

[00youknowit00]

Okay, well I think I'll do it with kh/ph tests, the drop checkers I saw were like $30-$50 and I don't wanna spend that much on one when I can get a $5 test kit.

 

[mfdrookie516]

$30-50? Are they gold plated with diamond inlays? I paid $10 for a pack of 3 on ebay.


As to the kH, pH thing... technically, Aqua Chem is right, though it's such a small change, a hobbyist level kit probably wouldn't detect it (or so I've read). If co2 caused a drop in kH, it would have a detrimental effect on fish, as it would be bouncing up and down on a daily basis.

 

[00youknowit00]

$30-50? Are they gold plated with diamond inlays? I paid $10 for a pack of 3 on ebay.

As to the kH, pH thing... technically, Aqua Chem is right, though it's such a small change, a hobbyist level kit probably wouldn't detect it (or so I've read). If co2 caused a drop in kH, it would have a detrimental effect on fish, as it would be bouncing up and down on a daily basis.

Hmmm, I just googled it on my phone and saw the first ones as that and was like ” NOPE!” Haha, my fault for giving up to quick!

 

[mfdrookie516]

Here ya go...

Aquarium Glass Drop Checker x3 for Co2 Monitor Tester | eBay

And you'll either need this - 4 dKH Reference Solution For Co2 Drop Checker pH | eBay (one bottle will last a long time, since you only use a few drops at a time, and only replace every couple months)

Or you can make your own if you have a gram scale and kH test - http://www.aquariumadvice.com/forum...ce-kh-solution-for-co2-measurement-88293.html


You'll also need bromethyl blue.. but if you have a liquid pH test kit, you can use it (same stuff). Just takes 2-3 drops.

 

[00youknowit00]

Here ya go...

Aquarium Glass Drop Checker x3 for Co2 Monitor Tester | eBay

And you'll either need this - 4 dKH Reference Solution For Co2 Drop Checker pH | eBay

Or you can make your own if you have a gram scale and kH test - http://www.aquariumadvice.com/forums/f24/how-to-make-a-reference-kh-solution-for-co2-measurement-88293.html

Wow! Didn't mean for you to do all that! But thanks a lot! know what I'll be getting next!

 

[aqua_chem]

With the same idea, the H2Co3+ (Diffused CO2) will react with the OH- ions. This reaction will cause more H20 to break up into H+ and OH- ions. Because some H+ where already present, this shifts the ratio thereby decresing pH and making the water acid!!

Thats it!

Right, but for each proton that disassociates from carbonic acid, another bicarb enters the system, raising KH. So KH will never decrease as acidity increases as a cause of CO2.

H2CO3 <----> H+ + HCO3-

 

[maxwellag]

We are off topic, aren't we?
Edit: nevermind, I didn't read the whole original post, sorry.... I should really make sure I do.

 

[mfdrookie516]

No ...

 

[00youknowit00]

We are off topic, aren't we?

Not really, I see it appropriate if I'm the one who started the thread, and asked a question about how co2 affects ph/kh, all that's happening is a little friendly debate on how co2 affects ph/kh, I find it completely acceptable.

 

[maxwellag]

Not really, I see it appropriate if I'm the one who started the thread, and asked a question about how co2 affects ph/kh, all that's happening is a little friendly debate on how co2 affects ph/kh, I find it completely acceptable.

My bad, didn't read your first post. Sorry bout that