# [Wet Thumb Forum]-Low kH and baking soda?



## dennis (Mar 1, 2004)

Hey all, quick question. My tap kH has lowered from 3 to 2. This is making the DIY [email protected] a bit problematic. I don't know what my Gh is. Does that matter. I have heard that baking soda can be added to raise the kH. Does this work well and if so what should I raise it to. Thanks alot.

Dennis Dietz

http://webpages.charter.net/dennisdietz/Aquatic%20Endeavors.html


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## dennis (Mar 1, 2004)

Hey all, quick question. My tap kH has lowered from 3 to 2. This is making the DIY [email protected] a bit problematic. I don't know what my Gh is. Does that matter. I have heard that baking soda can be added to raise the kH. Does this work well and if so what should I raise it to. Thanks alot.

Dennis Dietz

http://webpages.charter.net/dennisdietz/Aquatic%20Endeavors.html


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## Roger Miller (Jun 19, 2004)

In this case GH doesn't matter. You can add 1.1 teaspoons of bicarb per 50 gallons of water to get 1 degree of KH. Your tank would do fine with 3 - 4 degrees KH.

Roger Miller

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_"The indispensible first step to getting the things you want out of life is this: Decide what you want" -- Ben Stein_


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## dennis (Mar 1, 2004)

Thanks Roger. I check out Rex Gregg's FAQ because I remembered seeing something about it there. He said 1 teaspoon will raise 13 gallons 4 degrees. Quick math and you are both the same. I have added .5 teaspoon to my 10 gallon, wiht a water change. that should raise my kh about 2 degrees. I just tested it and I now have a kh of 4.5. Excellent. Do you forsee anyproblem with doing this? Does 4.5 seem like a good number? At a water change I want to replace the bicarb based on my amount of water changed. Correct? If i normally change 25% then i would add .125 or 1/8th of a teaspoon to the new water? Thanks aqain for hte fast response.

Dennis Dietz

http://webpages.charter.net/dennisdietz/Aquatic%20Endeavors.html


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## gsmollin (Feb 3, 2003)

Don't forget you are adding sodium to the water as well as bicarbonate. I don't know if that will be a problem in your water or not. I can recommend aragonite gravel for a low KH situation. It contains only calcium carbonate, and won't add sodium. How much to add is usually experimental. I put only a few tablespoons in a bag in my filter. Some add quite a bit to the gravel. You can adjust it easily, add some, then remove it, since the solubility is so low.


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## Roger Miller (Jun 19, 2004)

Gsmolin is right that you are adding sodium with the bicarbonate and that is a potential problem. The problem comes up when the sodium concentration is several times higher than the concentration of calcium or magnesium (GH). You can't analyse for sodium, so it's necessary to use KH as an indicator for the amount of sodium that's added. I don't know exactly where the safe cutoff is. To be reasonably safe you need to keep your doses so that KH doesn't exceed GH by more than a factor of 4 or so. If you have 2 dGH then that means you need to keep KH below about 8.

If you had a consistent problem with low KH then it would probably make sense to avoid the problem by using calcium carbonate as gsmolin suggests. If it's a temporary problem then sodium bicarb is a more flexible solution.

Roger Miller

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_"The indispensible first step to getting the things you want out of life is this: Decide what you want" -- Ben Stein_


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## dennis (Mar 1, 2004)

Thanks. Ill look into a more perminant solution but for now this should be fine. Unless my gh is 1 or less I should not have aproblem. Thanks for all the help. This will be intresting to see if and how things behave differently. Kind of exciting really. Like setting up a tank some place new for the first time.

Dennis Dietz

http://webpages.charter.net/dennisdietz/Aquatic%20Endeavors.html


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## Rex Grigg (Jan 22, 2004)

That's why I prefer to use calcium carbonate to raise both kH and gH.










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## dennis (Mar 1, 2004)

If i remember right you can get that at home brew shops right. Any other source?

Dennis Dietz

http://webpages.charter.net/dennisdietz/Aquatic%20Endeavors.html


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## Rex Grigg (Jan 22, 2004)

I have really not looked for calcium carbonate anywhere else. I'm lazy and drive right by a home brew shop every day







But I seem to recall that some people have found ordered it at a pharmacy but that could be rather expensive.

One of the bigger minds here must know where else to find it.










American by birth, Marine by the grace of God! This post spell checked with IESpell available at http://www.iespell.com

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## Planted Engineer (Jan 15, 2004)

my TAP KH=3 so till today I used to add sodium bicarbonate because low KH means jumps in the PH for slightes change in CO2 and everybody were recommending against such a low KH. I thought that sodium was for free... but now I understand that I should avoid high (K+Na)/(Mg+Ca) ratio...







so... - since I have a PH controller, a good ph controller then I can afford to have even a takashi Amano's KH=2. No?









PE.


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## dennis (Mar 1, 2004)

If yuo have a pH controller then you should be all set providing you have nothing in your tank that will affect the kh or ph by adding co2. Co2 forms an acid when it mixes with water.. Carbonic acid, i think. I believe that is why regular air line tubing getts funny underwater with co2 going through it. Mabey I am wrong there. If you have someting in your tank like... limestone rocks (calcuim carbonate), crushed coral, a lot of driftwood, etc, then the carbonic acid (which also causes the pH to drop) will cause these things to dissolve faster thus raising the hardness of the water (kH) raising the pH which causes the controller to injuct more co2 to lower the pH, soon your co2 levels are very high....... a horrible cycle has started! You should be fine just be aware of the things you have in your tank. Make sure all rock and gravel is inert, no coral on bags in the filter, etc. If in doubt, keep a close eye on the kH for a few days or remove fromthe tank anything you are unsure of until you can test it. Just be careful of your K dosings which you already know.

Dennis Dietz

http://webpages.charter.net/dennisdietz/Aquatic%20Endeavors.html


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