FishProfiles.com Message Forums

Hey Guys,

Would like to know if there is a chart or a format on how much Baking soda to use to bring the KH up by 1deg at a time for a certain amount of water volume.

Thanks in advance for any info.

Cheers
Wayne

Here is a handy calculator: http://www.dataguru.org/misc/aquarium/calKH.asp



__________
"To steal ideas from one person is plagiarism; to steal from many is research."
researched from Steven Wright

Thanks so much for that Bob.. helped me out heaps.

IS there a calculator like this for GH?

My tanks GH is sitting at 8deg and l would like to know how much l need to get it up to 10deg.

Cheers
Wayne

This page should help somewhat.

This page is an interactive calculator for calcium-based hardness which should also help.

This table of conversion units will allow you to work out how much calcium carbonate you need in order to create the water hardness you need. It converts all the major measurement units into each other in a simple table lookup.

So, from the table, 1° dH is equal to 17.86 parts per million of calcium carbonate per litre of water. 1 part per million is equal to 1 milligram of calcium carbonate per litre of water, so to increase the hardness by 2° dH, you need to have 2 x 17.86 = 35.72 milligrams of calcium carbonate per litre. Of course your problem from here on in is that if you're converting an aquarium of modest size, say 20 US gallons = 75 litres, then you're still going to have to measure fairly small masses with reasonable accuracy, so your total calcium carbonate input will still be of the order of 1.3 grams for a 20 gallon setup. That's not much to weigh accurately unless you have access to a chemist's micro-balance!

Of course, Rift Lake owners aiming for very hard water don't face this problem - when you're aiming for something like 50° dH in 100 gallons, you're dealing with much more manageable quantities, and a small error in mass measurement isn't going to make that much difference - plus a Rift Lake keeper will be using a calcareous substrate and limestone rocks for decor in any case, which should buffer the hardness considerably!


Panda Catfish fan and keeper/breeder since Christmas 2002

sharkbait,

I found Bob's caculator interesting. Not because I didn't know how much Baking Soda I need to change my KH, but because I tried the caculator and looking at the results it made me scream "WHAT?". The value seemed way too high to me, but then I understood where my confusion came from.

I would like to share this with you to avoid any potential misunderstanding, just in case:

The calculator gives you the tsp measurements for a "non-seeded" tank, meaning the very first time you add Baking Soda. After that, you should only add the number of tsp for the volume of water that you removed (and that is where my confusion was). Example: let's say that you need 2tsp to raise your entire tank water from the starting KH to the one you desire. Now you do a 50% water change. After that you would have to add 1tsp to maintain the higher KH.

Hope this helps,

Ingo

---

Proud Member of the New Jersey Aquatic Gardeners Club

Thanks Calilasseia and Ingo for your help.

So far my tank is at
PH 7.0
GH 10deg
KH 7deg
C02 around 18-25ppm

My goal is to keep my KH around 5-7deg. With a tank of 160lt in volume (not size of tank)...
If my KH was at 5deg and wanted to rasie to 7deg - I would have to add 1.62 tsp (7.9mils) of baking soda.
If my KH was at 6deg and wanted to rasie to 7deg - I would have to add .81 tsp (3.9mils) of baking soda.

Correct me if l'm wrong guys.

Ingo you said "The calculator gives you the tsp measurements for a "non-seeded" tank, meaning the very first time you add Baking Soda. After that, you should only add the number of tsp for the volume of water that you removed"
I do this with my GH and its working well.
With KH I always thought it will go down over time weather or not you do a water change.

sharkbait,

If my KH was at 5deg and wanted to rasie to 7deg - I would have to add 1.62 tsp (7.9mils) of baking soda.
If my KH was at 6deg and wanted to rasie to 7deg - I would have to add .81 tsp (3.9mils) of baking soda.

That sounds like a lot to me. I vaguely remember that I initially calculated similar high tsp numbers when estimating the need to raise the KH by 2 degrees for my 125. Luckily I started off using only half that dosage and what can I say, the KH was up by 2.
Currently, I use 2tsp of baking soda to raise my tank by 2 degrees after a 60 Gallon water change (yes, 60G of new water). Moral - add less, let the tank settle for a few hours - check before adding more.

With KH I always thought it will go down over time weather or not you do a water change.

You know what? I don't know that, and it may well be, but - Not doing a water change should not be an option anyway , right ?

Ingo

---

Proud Member of the New Jersey Aquatic Gardeners Club

Hey Guys,

Just want to update you all on my outcome.

Last night l tested my KH. It was down to 5deg. From the info l posted above and taking Ingo's thoughts into account l only put half the amount of baking soda into the tank.

I wanted to raise my KH back up to 7deg, but only put in half the amount to only raise it by 1 deg and then test to see what my outcome was.

So by doing this l only put in .81 tsp (3.9 mils) of baking soda.

And guess what!!! l tested the KH this morning and it was up by 1 deg (6deg). I ended up putting another 3.9mils of baking soda and will test tonight to see if it is at 7deg.

Ingo... looks like my calculations are spot on.

sharkbait_whohaha,

Very interesting

Keep us posted as I for sure would like to know the outcome.

Maybe I have to retest mine.

Ingo

---

Proud Member of the New Jersey Aquatic Gardeners Club

Hey all.

I did another test last night. My KH is now sitting on 7deg.

If anyone wants me to work out how much baking soda they need to raise to certain KH level.. Just post your detail:
KH now
KH you want
Water volume in tank (not actual tank size)

Cheers
Wayne

Wayne,



But I think the advertisement of being the Baking Soda man comes a little too early

So basically you say that the initially suggested dosage did exactly what it was supposed to do. That is good, but how do you explain then that half the dosage does it for me?

From a volume perspective, my values should be more accurate as I replace a much larger tank volume (60G every week during a water change) and add much larger total quantities of Baking Soda back in (about 2.5tsp to raise KH from about 1dH to maybe 3.5dH).

An option here would be that my test kit (liquid) is way off, but KH test kits are among the most reliable (to my knowledge).

Maybe one has to consider existing KH values as well and yours fit the standard measurements because you already have a start value of 5dH and I have only 1dH.

Or maybe it has something to do with the GH, the higher it is the more Baking Soda you would need to raise the KH.

I am most certain that my KH is in the mentioned range as I tested it rather frequently (at least 8 times) during the last 6 months, on various occasions like morning, evening, the day (or less) after adding Baking Soda, and multiple days later.

So, any ideas?

Ingo

---

Proud Member of the New Jersey Aquatic Gardeners Club

Sorry to interrupt the conversation guys but I need some advice on water hardness too!

The KH of my tap water is 2.8dH and the KH of my tank is 1.7dH. I've been monitoring my pH and unsurprisingly its not very stable and tends to drop pretty quickly. I'm going to try raising the KH in the tank using the baking soda method but was wondering what is a good KH value for me to aim for? I want the pH to remain stable and at the same pH as my tap water which is 6.8.

I'm not sure why the KH in the tank is dropping lower than my tap water as my substrate and rocks are inert as far as I know. I have a large piece of driftwood so maybe its that? My plants are all of the fake silk variety!

I also tested GH and its 11.2dH in the tank, but my tap water is 7.8dH so really don't know whats going on there!

The tank is a 15gal with ammonia 0, nitrite 0, nitrate 5-10ppm, pH 6.2 (but very unstable), temp 25C. Its been up and running about 6 weeks.

I am keeping tiger barbs and zebra danios.

Hope thats enough info! Thanks!

Ingo,

The last thing l want to be known as is the baking soda man.. hahaaha. From my stable results l have been getting all l want to do is share this with others and give them a base starting point.

In regards to why you only need half the dosage to get your result is something l cant explain. There is always going to be factors to consider when doing testing and add anything to your tank. I.e.

1)What is the exact water volume in your tank? I have notice when people talk about the amount of water they have in their tank they use the calculator to work out this (tank size), but dont take into consideration when they put gravel, rocks, driftwood, internal filters, heaters in that this will take up room and less water is in the tank. For me.. When l had setup my tank l had placed everything in the tank, then for every 10lt of water l put in l had marked it on the glass. This gave me a spot on water volume.

I have a 48"x14"x18" High tank.. The cal say l have 198.2lt or 52.4 Gal. When l had everything in the tank l was only able to get 160lt or 42.2 Gal. Thats almost 20% difference.

2)What are the parameters of you tab water. I test mine very month and l know where my water comes from. In this case, Im lucky with the KH and GH as we dont have any in our tap water.

3)When do people do their water testing? I do a water change on Sundays, then l test the water on Wednesdays. This giving heaps of time for the water to mix well. If you do a water change, then test your water 1-2 hours later you will not get a very clear result. I have tested this out on a number of occasions. This goes for adding chems into your tank to. You will get a clearer result after 24hours.

In saying this.. If your tap water has some KH in it and you do a water change, you should wait at least 24hrs before testing the tank water and adding in any chem. (baking soda). This maybe the reason why you only need half the amount as your tap water has KH in it already.

There would be a lot more factors to think about, but l can only think of these right now.

If you want an end result of KH 9deg and your starting value is 1 deg or 5 deg it will not make a difference in the way you calculate how much you need… only the quantity will be different. Thats if you have already done your water change 24hrs or more before hand.

About the GH affecting the KH, l can comment on this as you may have found finds there GH may affect KH. So far all the research l have done has not mentioned anything about a value of GH will affect KH results. If this was the case, l guess the KH calculator would need and extra value (GH value) in the equation.

Cheers
Wayne

Hi foj1428,

I'm not sure why you are getting these results. As far as l know, driftwood would only affect your GH (make it softer), but in your case its not. Are you 100% sure your rocks and gravel does not affect your water params?

Ok.. with your GH, do you add conditioning salt to the water? If so, how much and how many times?

With KH a good start would be to have a min or 3ppms… others please correct me if l'm wrong here.

When you do a water change how much do you do? How often?

What type of filter do you use and what media do you have in it?

Do you have an airstone running in your tank?
When do you do your water testing?

Wayne,

The last thing l want to be known as is the baking soda man

I would assume that the difference between net-water volume and full tank volume in my tank is less significant than it would be in smaller tanks, it is a 125G.

You state that your tab KH is zero, but at the original post you say that you would like to raise it from 5 to 7. How did you get the first 5? Same calculations? My tab is 1KH and I raise it only to 3 or 4 (beginning 3, now to 4 to have more CO2 in the water).

If our values and experiences differ so greatly then there must be some factor(s) that we don't consider. I wonder what that would be. Oh, and I measured my KH on all kinds of occasions, but never straight after adding Baking Soda as I know that these results would be irrelevant.

Ingo

---

Proud Member of the New Jersey Aquatic Gardeners Club

Driftwood will drop ph and sometimes with a low starting kh it will drop it considerably. As low as 5.0 wouldn't be impossible. My only guess for an increase in gh is that one of your rocks isn't quite as inert as you thought. I wouldn't worry about the gh unless it's continually rising and just work on buffering the kh beyond 3. If your ph is still unstable I'd buffer it up to at least 5. I don't know what that takes in baking soda because I prefer to use a commercial buffer, kent ph stable, for buffering my ro water. It also raises ph instead of just kh and currently I'm buffering it to 5dkh, 7.2ph.

Ok, I'm not 100% sure about the rocks but I was told by my LFS they wouldn't affect water chemistry. Is there any way to test?

I don't use salt.
Water changes are 15% weekly using water that has aged 24hrs. I use King British water conditioner too just to be on the safe side.

My filter has no chemical filtration but it does have ceramic media in it to help with biological filtration. Could it be due to ceramic media?

I tested the water just before I did a water change and it was GH 11.2, KH 1.7 and pH 6.5. I tested the water again 24hrs after a water change and it was GH 10.1, KH 1.7 and pH 6.7. I intend to test again in a couple of days to see if anything starts to drift.

I'm not too worried about GH as its well within the range suitable for my fish, though it is a bit baffling as to whats going on with it!