# is adding baking soda to raise KH safe?



## Quagulator (May 4, 2015)

CaSO4 for Ca - target 20-30ppm into your incoming RO water. 
MgSO4 for Mg - target 5-15ppm into your incoming RO water. 
KHCO3 for kH - Target 0.5 - 1.0 degrees of kH

Target a full 1.0 drop in pH from using CO2. You can likely get up to a 1.2 drop - 1.4 drop in pH from CO2, but keep a careful eye on live stock.


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## Edward (Apr 11, 2005)

Adding 2 dKH with baking soda increases Na by 16 ppm. This amount is harmless to plants and fish, in contrary it can actually be beneficial to both and is widely available.


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## Ddrizzle (Jan 30, 2019)

I use a mix of baking soda and potassium bicarbonate myself.


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## CarissaT (Jul 1, 2019)

I don't think the drop in pH by adding co2 is affected by your KH. And that type of drop doesn't have much effect on fish, every day the pH will go down by about 1 while co2 is injected (if you are shooting for about 30ppm) and go back up at night afterward when shut off. But low KH will cause things like nitric acid or other waste products lower your pH much more quickly, this is a concern. And I've used baking soda for raising KH, no ill effects as long as you don't do it too suddenly. But if you are on top of water changes and keep things clean, and don't have anything in your tank that can acidify water (like driftwood), even with a low KH you can be just fine.


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## somewhatshocked (Aug 8, 2011)

As others have indicated, CO2 forms carbonic acid when it hits your tank. That's what allows for the perceived drop in pH. Carbonate hardness is not impacted and osmotic pressure won't change for your critters.

kH of 1-2 is fine and it's what I aim for in most of my regular, non-Caridina (shrimp) tanks. 1-2 is plenty for stable parameters.


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## Here_To_Learn (Jul 18, 2016)

Quagulator said:


> KHCO3 for kH - Target 0.5 - 1.0 degrees of kH






somewhatshocked said:


> kH of 1-2 is fine and it's what I aim for in most of my regular, non-Caridina (shrimp) tanks. 1-2 is plenty for stable parameters.




are you guys saying from 0.5 to 2 degrees of KH is fine? I'm a little puzzled because I read on this website that harlequin rasbora needs 6 kh at least! https://www.liveaquaria.com/product/1065/harlequin-rasbora?pcatid=1065&c=830+887+1065

and Endler's livebearer needs at least 10 all the way up to 30! https://www.liveaquaria.com/product/1584/endlers-livebearer?pcatid=1584&c=830+1100+1584

very confusing


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## Quagulator (May 4, 2015)

Here_To_Learn said:


> are you guys saying from 0.5 to 2 degrees of KH is fine? I'm a little puzzled because I read on this website that harlequin rasbora needs 6 kh at least! https://www.liveaquaria.com/product/1065/harlequin-rasbora?pcatid=1065&c=830+887+1065
> 
> and Endler's livebearer needs at least 10 all the way up to 30! https://www.liveaquaria.com/product/1584/endlers-livebearer?pcatid=1584&c=830+1100+1584
> 
> very confusing


Simply put, they are wrong. I have never ever seen a tank with a kH above 2 and a pH of less than 7. It simply can't happen unless you are using CO2 to keep pH down. 

Raising kH above 1 degree and your pH will be ~7.1. Raise your kH to 6-10 degrees, your pH will be pushing high 7's if not 8. 

Using a buffering substrate, ADA soil , Tropica soil etc. will keep tank water @ 0 degrees kH and pH at around 6.5.


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## Asteroid (Jul 26, 2018)

Here_To_Learn said:


> are you guys saying from 0.5 to 2 degrees of KH is fine? I'm a little puzzled because I read on this website that harlequin rasbora needs 6 kh at least! https://www.liveaquaria.com/product/1065/harlequin-rasbora?pcatid=1065&c=830+887+1065
> 
> and Endler's livebearer needs at least 10 all the way up to 30! https://www.liveaquaria.com/product/1584/endlers-livebearer?pcatid=1584&c=830+1100+1584
> 
> very confusing


That is either wrong information or it's just a misprint. Harleys can live in a pretty wide range of water hardness. I've kept a large school for years with a KH of 1 to 2. Check other sources, I bet they don't give a KH of 6+


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## Edward (Apr 11, 2005)

Quagulator said:


> Using a buffering substrate, ADA soil , Tropica soil etc. will keep tank water @ 0 degrees kH and pH at around 6.5.


 +1

ADA Amazonia substrate is acidic and will keep water at 5 - 6 pH and pushing KH to zero degrees. Nothing wrong with that, plants and fish love it, except African Cichlids of course. And there is no such thing as pH crash, only too fast rate of change. Peat moss can push pH lower than CO2 and fish still love it.


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## Here_To_Learn (Jul 18, 2016)

Ok thanks, that is very helpful. 

we are using Aquasoil amazonia light. should I be just raising the GH on my RO water and pour it in the tank for water changes? how far does the substrate buffer go? will the substrate lose its buffering ability?


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## Quagulator (May 4, 2015)

Here_To_Learn said:


> Ok thanks, that is very helpful.
> 
> we are using Aquasoil amazonia light. should I be just raising the GH on my RO water and pour it in the tank for water changes? how far does the substrate buffer go? will the substrate lose its buffering ability?


gH boost only (Ca and Mg).

No kH needed (buffer). The soil's buffering will last it's lifetime if you us gH boosted RO water. or.. it will break down into muck over a few years before it loses its buffering ability.


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## Edward (Apr 11, 2005)

ADA substrates are the most common substrates used in Japan, Hong Kong and Singapore and they have 
very soft water 0.3 – 4.4 dKH and it works perfectly for fish and plants. More tap water parameters


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## Edward (Apr 11, 2005)

In addition, ADA is selling Softenizers to lower KH even further, cation exchange resin.


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