PH, CO2, and KH

[Fishfiles1]

so i have noticed with charts that if you have a low PH and High KH you have a High amount of co2 in the tank, My water runs neutral but the Kh is always low, so my question, does Co2 lower Ph and Kh or just Ph, and Does the Kh have an effect one how much Co2 gets into the water.
my tank is a 5 gallon planted and is using 2 2letter DIY co2 tanks, and my Ph is 6.8 and Kh of 2, but this Kh stays the same with Co2 and with out, but the Ph will drop or raise.

is there something i can put into the tank to raise just the Kh
Thank you all, i understand if this is a hard question

 

[DoctaQ]

co2 isnt supposed to affect the kh, but the weird thing is that people say that baking soda is only a temporary fix for raising the kh, which ive always found interesting because it is used in reef tanks without any of the aurora of only being temporary.

so i guess my suggestion for raising kh and subsequently ph is alk booster by seachem.
baking soda could be an experiment.

 

[Canuck]

Baking soda is temporary in two cases. The first is if you do water changes without replacing the carbonate (baking soda) that is dissolved in the water you take out. The second is when carbonate (baking soda) is consumed by nitrifying bacteria or plants, such as vals, that will consume carbonate as a source of carbon. Under normal tank conditions consumption of carbonates (baking soda) is limited and will have a minor effect (undetectable) on carbonates. Similarly, the carbonic acid formed by dissolved CO2 will consume kH at undetectable levels. Many suggest coral or shells as a "permanent" solution since they will continously dissolve releasing carbonates (and calcium) into the water resulting in a long lasting hardening effect on water.

The CO2 charts assume kH (or carbonates) are the only buffer in the water tested. If the chart indicates any more than approximately 3 ppm of CO2 at equilibrium then the chart can't be used to calculate CO2 due to other buffers in the water.

Hope I explained that understandably.

 

[Fishfiles1]

wont adding a carbon source also raise my PH

 

[jpappy789]

CO2 forms carbonic acid when dissolved in water...lowering the pH

 

[Canuck]

carbonate and bicarbonates (baking soda and calcium carbonate) will raise your ph. Nothing will raise carbonates without also increasing pH. Raising or lowering kH has no effect on CO2 content.

 

[timwag2001]

you dont need to mess with your kh.

 

[timwag2001]

the only way to get more co2 is to add more co2. leave your kh alone, you'll be fine

 

[jmhart]

the only way to get more co2 is to add more co2. leave your kh alone, you'll be fine

:iagree:

 

[Cerianthus]

CO2 is in direct relation to Bicarbonate ion and with carbonate ions.

H+ + CO3--(Carbonate ion) would yield HCO3- (bicarbonate ion) and add another H+ to bicarbonate ion will yield H2CO3 (Carbonic Acid). They will shift back and forth as per factors which will influence the direction of association and/or dissociation. Of course addition of one will affect others.

Google Carbonic Acid: Should be able to obtain association/dissociation equations (Equilibrium)