# Alkaline Buffer vs Baking Soda?



## ChrisX (May 28, 2017)

I used to use Alkaline Buffer and about three months ago switched to baking soda. Raising KH from 2 to 4ish to buffer pH.

Would this affect a high tech CO2 tank in any way? Equivalent?


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## natemcnutty (May 26, 2016)

ChrisX said:


> I used to use Alkaline Buffer and about three months ago switched to baking soda. Raising KH from 2 to 4ish to buffer pH.
> 
> Would this affect a high tech CO2 tank in any way? Equivalent?


Baking soda is fine, but it does affect CO2 concentration. You will need to adjust CO2 to compensate.

Personally, I run between 1-2 dKH in most of my tanks without issue. I'd leave it alone if I were you


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## Zorfox (Jun 24, 2012)

natemcnutty said:


> I'd leave it alone if I were you


I second that! In my opinion, hobbyists should only raise KH when the inhabitants need it. The vast majority of our plants do quite well with very low levels, provided there is some other form of carbon. 

As far as the PH crash argument, I've personally never had it happen and think it's more a theoretical thing. Many seem to forget that bicarbonate is not the only buffer in nature i.e. phosphates.


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## SamuelLG (Dec 24, 2017)

Alkaline buffer is pretty much baking soda (NaHCO3 → sodium bicarbonate) mixed with a little bit of other bicarbonates (potassium, magnesium), but the main ingredient is baking soda, so there is no practical difference between using Alkaline buffer from Seachem or baking soda to raise KH.

Regarding the effect on CO2, I'm pretty sure bicarbonates doesn't interfere with the amount of CO2 you are putting into the water in terms of lowering it. Once the CO2 you add is dissolved, it will combine with a water molecule and release a proton H+, turning into a bicarbonate it self. That proton can stay free lowering the pH or being captured by a carbonate to transform into another bicarbonate preventing the pH to going down.

Only if the pH falls to bellow 5 most of the bicarbonates will turn into carbonic acid, so, increasing the amount of CO2 dissolved even more. If you keep putting acid into the water (H+ ions) all bicarbonate/carbonate will be transformed into carbonic acid and will be loss as of CO2 in gas form.

Adding baking soda to raise KH from 2 to 4 will only affect the pH given the specific amount of dissolved CO2. While 30 ppm CO2 in KH 2 will result into a pH around 6.3, with KH 4 the same 30 ppm CO2 will give you a pH 6.6.


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