# Increasing KH with Baking Soda



## rrguymon (Jul 10, 2005)

I want to increase the bicarb hardness in my water. I have read adding baking soda will do it. 

I am concerned that adding baking soda to the tank after a water change will stress the fish? If you treat the water with baking soda do you need to treat the water first out side the tank?

Thanks Rick


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## Rex Grigg (Dec 10, 2002)

You will still need to treat the water for chlorine/chloramines just like you do now. Then you need to slowly increase the kH and pH of your water with the baking soda.

What is the kH of your tap water? And do you have a water softener?


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## Wasserpest (Jun 12, 2003)

I would dissolve the baking soda in some water and add it as you add the new water during water changes, along with the de-chlor.


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## Hypancistrus (Oct 28, 2004)

I use Seachem Alkaline Buffer which is basically expensive baking soda. roud:

I also use RO water for water changes and remineralize it _after_ adding it to the tank.

On a 15 gallon water change, I add about 1.5 teaspoons of Alkaline Buffer. I dissolve it in 500 mL of water first. When I dump it in the tank after the water change, I don't see any stressful reactions from any of my fauna.


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## Rex Grigg (Dec 10, 2002)

Hypancistrus said:


> I use Seachem Alkaline Buffer which is basically expensive baking soda. roud:
> 
> I also use RO water for water changes and remineralize it _after_ adding it to the tank.
> 
> On a 15 gallon water change, I add about 1.5 teaspoons of Alkaline Buffer. I dissolve it in 500 mL of water first. When I dump it in the tank after the water change, I don't see any stressful reactions from any of my fauna.


That's because your tank water is already equal to your new water. If one were to take a tank of low pH/kH water and suddenly raise both the pH/kH you might well stress the fish.


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## rrguymon (Jul 10, 2005)

Ok thanks all. I have really wierd water out here in the desert. A KH of 7 but it appears almost none of the KH I read on test kits is composed of bicarbonate. I am running at at PH of 6.1 and I think I still need to add more Co2. Still have some BBA.

I don't want to go lower on the PH so I might try and just add baking soda to raise my KH by 2 and then slowly increase the co2.

Rick


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## Hypancistrus (Oct 28, 2004)

Rex Grigg said:


> That's because your tank water is already equal to your new water. If one were to take a tank of low pH/kH water and suddenly raise both the pH/kH you might well stress the fish.


That's a very good point. If you always keep your kH at 6 dKH for example, then one day when you do a water change decide "hmm, I want my dKH to be 12 now," then add baking soda to equal that, the fish will be stressed because they are not used to it.

So for _maintaining_ kH, it's safe to add, but for _changing_ kH, add only a bit per day (if for some bizarre reason you want to do this).


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## shalu (Jan 16, 2003)

Has anybody seen concrete evidence that adding a few degrees of KH with baking soda in one shot stresses fish? I haven't, not that I do that regularly.


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## Spar (Aug 7, 2003)

shalu said:


> Has anybody seen concrete evidence that adding a few degrees of KH with baking soda in one shot stresses fish? I haven't, not that I do that regularly.


I have gone from 3 to 5 to 7 (2-day period) and 7 back to 3 (2-day period), no problem.

I also have nearly bi-daily 1dKH flux's in my 180g. But KH is usually between 1 and 2 anyway, so not very buffered! I add Baking Soda up 1/2d every 2 days. and do a 75% water change per week to keep KH in check.


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## londonloco (Aug 25, 2005)

Be very very careful. I did this on my reef once, and all i got out of it was dead inverts...my fish were fine...but my kh sky rocketed and it took a week of water changes to get it back to normal....was the end of my baking soda days.... :icon_redf


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## shalu (Jan 16, 2003)

londonloco said:


> Be very very careful. I did this on my reef once, and all i got out of it was dead inverts...my fish were fine...but my kh sky rocketed and it took a week of water changes to get it back to normal....was the end of my baking soda days.... :icon_redf


how high is skyrocket? Did you calculate the wrong dosage? I imagine saltwater inverts might be more sensitive. On the other hand, my cherry shrimp seem to take the hot discus temperature, all kinds of discus medication in strides :icon_bigg , although I did catch one discus trying to swallow a shrimp and spit out half of it in the end.


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## Hypancistrus (Oct 28, 2004)

shalu said:


> Has anybody seen concrete evidence that adding a few degrees of KH with baking soda in one shot stresses fish? I haven't, not that I do that regularly.


I have not tested it myself (too much time, effort, etc.), however it follows if you for some reason needed or wanted to do a large kH change I would do the adjustment by a few degrees every day or so.


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## shalu (Jan 16, 2003)

I was only asking because I doubt a few degrees sudden KH change will cause any problem, did it a few times. And a few degrees is what most people need anyway. I have also dosed quite a few different ferts/meds by a few tablespoons in my 100gallon, never any issues.


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## scolley (Apr 4, 2004)

I move my tanks up 1 to 1.5 degrees KH with my water change every week using baking soda. I just dissolve it in a cup of water and unceremoniously pour in right after the water change. I have never seen any indication that this small, but fast, change stresses the fish at all.


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## rrguymon (Jul 10, 2005)

Thanks again for all the replies. The consenses seems to be I can just mix the baking soda with water and pour it in during or after the water change as long as I don't try a large adjusment. 

Rick


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## Rex Grigg (Dec 10, 2002)

1° of kH is not going to be a huge change. But the huge pH swing when doing more than a degree or two is what could cause problems.

Baking soda is powerful stuff. I remember helping one person and when they found out the baking soda would raise their kH they figured that just over 1/4 cup in a 29 gallon tank would be fine. Took their kH from around 1° to around 25° and the pH from right around 7° to around 8.1° as I recall. Most of the livestock in the tank went belly up.


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## rrguymon (Jul 10, 2005)

Rex Grigg said:


> 1° of kH is not going to be a huge change. But the huge pH swing when doing more than a degree or two is what could cause problems.
> 
> Baking soda is powerful stuff. I remember helping one person and when they found out the baking soda would raise their kH they figured that just over 1/4 cup in a 29 gallon tank would be fine. Took their kH from around 1° to around 25° and the pH from right around 7° to around 8.1° as I recall. Most of the livestock in the tank went belly up.



Thanks. I was thinking more like 1/2 tsp at water change time and doubling the dose every week. I would do this until the KH reading after a water change was a couple degrees higher than the Tap. Do you think that is too much? 

Rick.


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## zig (Jun 4, 2005)

Heres a calculator you might find useful, it shows the change you can expect in Ph as well as Kh as you add the soda, it works for any tank size, just add your numbers it calculates the rest.

KH calculator


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## scolley (Apr 4, 2004)

zig said:


> Heres a calculator you might find useful, it shows the change you can expect in Ph as well as Kh as you add the soda, it works for any tank size, just add your numbers it calculates the rest.
> 
> KH calculator


Just in case it causes anyone confusion in checking the math, the aforementioned calculator appears to be using a factor of 13 liters to a US liquid gallon, yielding several percent difference to any more precise attempts to use the "_1 t baking soda in 50 liters of water to raise KH by 4 dh_" formula.

On an different note, I've seen the above quoted all over the place, and I used it for quite a while to calculate how much Arm&Hammer baking soda to use to raise my kH. But a few hours after adding the baking soda, I used to _always _ find my kH lower than I anticipated. I've finally settled on a different formula that gets me much closer, though it is still a shade low "_1 t baking soda in 50 liters of water to raise KH by 2.75 dh_".

This has been pretty consistent, albeit using that same exact box of baking soda for a year now. Short of taking pot-shots at my math or my ability to use a kH testing kit, any ideas why I might be experiencing this? Can anyone confirm that the "original" formula is indeed correct? This is quite repeatable in my tanks.


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## shalu (Jan 16, 2003)

scolley said:


> the aforementioned calculator appears to be using a factor of 13 liters to a US liquid gallon, yielding several percent difference


Steve, did you mean 4 litres to a US gallon? 1gallon = 3.79 liter


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## Spar (Aug 7, 2003)

also wanted to point out that fluctuations of pH due to KH changes don't appear to be a problem with fish in acidic conditions (not including the effects already present from co2 or tanics). I experience this on a weekly basis of keeping my KH in check in my 180g, with my Ray and Arowana. Non-planted, Non-co2-injected, Non-tanic'ed, etc.

If KH were .2dKH, for example, you have a pH near 5.0. if you even add 1/4 dKH, you can't escape a sudden pH change of near 1.5 full pH points. Seems huge, but fish don't react to it. Every now and then, I forget to add baking soda to my tank (which I keep at 1d KH on average), and notice my pH in the lower 5's. Doing a 75% water change raises that pH to 6.5-6.75 (tap is 2 dKH) instantly, due to the some-what small increase in KH.

So if you have acidic water, that is not due to acids (co2 or tanics), the pH swings are not near as severe as if you were to notice non-acid induced pH swings in alkaline water.

And although some may doubt this, Rays are known as some of the most sensitive fish in the hobby to fluctuations, and I have been getting away with this for almost 2 years now. 

In other words, I think that the focus on pH is significantly less important than the focus on KH ppm changes. Keep it less than 2d (36ppm) changes at a time, and things should be fine.

And don't do this 1d KH game I do without having a good dosing regime of re-adding baking soda (KH) back on at least a bi-daily basis.


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## scolley (Apr 4, 2004)

shalu said:


> Steve, did you mean 4 litres to a US gallon? 1gallon = 3.79 liter


 :hihi: Yea, sorry about that! Maybe you _should _ be questioning my math!

I meant to say "calculator appears to be using a factor of 13 liters to *50*  US liquid gallons", when it's closer to 13.2 liters for that volume. Left out the 50.

Try the calculator yourself. You'll see. But sorry about the bogus post!


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## shalu (Jan 16, 2003)

scolley said:


> I meant to say "calculator appears to be using a factor of 13 liters to *50*  US liquid gallons", when it's closer to 13.2 liters for that volume. Left out the 50.
> 
> Try the calculator yourself. You'll see. But sorry about the bogus post!


you are still not saying it right, Steve, :hihi:,
It should be "calculator appears to be using a factor of 13 * US gallons*  to 50 *liters* "


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## scolley (Apr 4, 2004)

duh! :wink:


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## scolley (Apr 4, 2004)

scolley said:


> On an different note, I've seen the above quoted all over the place, and I used it for quite a while to calculate how much Arm&Hammer baking soda to use to raise my kH. But a few hours after adding the baking soda, I used to _always _ find my kH lower than I anticipated. I've finally settled on a different formula that gets me much closer, though it is still a shade low "_1 t baking soda in 50 liters of water to raise KH by 2.75 dh_".
> 
> This has been pretty consistent, albeit using that same exact box of baking soda for a year now. Short of taking pot-shots at my math or my ability to use a kH testing kit, any ideas why I might be experiencing this? Can anyone confirm that the "original" formula is indeed correct? This is quite repeatable in my tanks.


This was bothering me, so I set up an experiment to reproduce this and prove the the formula I was suggesting is accurate. To make a long story short, I set up the conditions, established controls, tested multiple times, and got the results I expected, with minor variance (lack of test kit precision assumed the culprit the minor variance). In drawing up conclusions, I thought I had demonstrated that my formula worked, assuming the test kit was OK, and the measuring spoons were accurate. Uh oh.....

So I checked my measuring spoons (looked decent - but from Walmart) against my wife's sacred cooking dry measuring metal spoons. And guess what? My spoons were all about 1/3-1/4 too small! And I verified this against her secondary plastic spoons! Doooh!

So my problem has been using bad dry measuring spoons! I'm sure there are several lessons here, not the least of which is make sure your dry measuring spoons are accurate!

Greg Watson doesn't seem to sell these anymore. Anyone know where to get spoons you can trust. My wife is not giving hers up. :icon_frow


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## Rex Grigg (Dec 10, 2002)

How small of a set of spoons are you looking for?

If you want the really tiny ones then WalMart is normally a good source. But then again sometimes those are fractional tablespoons instead of teaspoons. If it's just the normal set of 1/4-1 tablespoon you can get those anywhere.


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## scolley (Apr 4, 2004)

Rex Grigg said:


> How small of a set of spoons are you looking for?
> 
> If you want the really tiny ones then WalMart is normally a good source. But then again sometimes those are fractional tablespoons instead of teaspoons. If it's just the normal set of 1/4-1 tablespoon you can get those anywhere.


Thanks Rex. Yup, that's all I'm looking for. But I got these at WalMart, and I was foolish enough not to confirm their accuracy before using them for a year or so. They looked nice, but _were_ plastic.

I guess the answer is pick a set and just have another set to confirm that they both measre the same. If they don't you know at least one set is wrong.


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## Laith (Jul 7, 2004)

scolley said:


> ...
> 
> So my problem has been using bad dry measuring spoons! I'm sure there are several lessons here, not the least of which is make sure your dry measuring spoons are accurate!
> 
> ...


Which is why I'd strongly recommend to get a simple digital gram scale. They can be found at very reasonable prices...


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## rrguymon (Jul 10, 2005)

Well I am at PH 5.9. The fish are fine not hugging the surface at all. My KH kit measures 7.5 and the algae is still growing. I have about 200 bubbles per minute going into the tank. I have an internal reactor I can see the bubbles in the tank water no leaks. The PH is also way down. Some thing is definitly screwy. It almost looks like I have no KH in the tank. Yet my tap water after sitting over night has a PH of 7.9 which is kind of in line with 3PPM. 


I am going to add baking soda next water change day for sure. I will put a known quantity of 4 KH into the tank slowly and then use that as my target PH for 35 or PPM CO2.


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## scolley (Apr 4, 2004)

Laith said:


> Which is why I'd strongly recommend to get a simple digital gram scale. They can be found at very reasonable prices...


I had to bump up my kH after a water change last night, using my wife's sacred stainless measuring spoons. Using the standard kH calculator formula put me _spot on _ to my target kH!

So much for thinking the formula was spotty... what was spotty was my crappy measuring spoons! But no more -got a digital scale coming in the mail today. Since the wife won't give up her spoons... Thanks Laith.


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## rrguymon (Jul 10, 2005)

I added a teaspoon of baking soda on water change day. Raised my KH about 1. With the same bubble rate my PH went up about .1 too. I will just add 1 teaspoon every week at water change day. It will keep my PH above 6. 

Rick


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