Please explain this to an idiot...

[PaulVerrall]

Cheers guys, I think I was starting to get it, what threw me was in the book of the test kit. It says drip the kh solution into the test water, for every drop, its 1 on the german carbonate hardness scale. So mine tested as 5. But the german hardness on the water site says 13.38. So they are 2 different, separate scales using the same name?

[Danmassey]

So they're two different measurements, but both use the same units - German degrees.
Your KH is 5 German degrees (or 90ppm)
Your GH is 13.3 German degrees (or 240ppm)



The G in GH stands for general hardness not German, in case that's where the confusion is coming from?

[codheadjohn]

Cheers guys, I think I was starting to get it, what threw me was in the book of the test kit. It says drip the kh solution into the test water, for every drop, its 1 on the german carbonate hardness scale. So mine tested as 5. But the german hardness on the water site says 13.38. So they are 2 different, separate scales using the same name?

Other way around, it's measuring 2 different things using the same scale.

General hardness (GH): The measure of magnesium and calcium dissolved in water.

Carbonate hardness (KH): The measure of carbonates and bicarbonates dissolved in water

Both are measured in German degrees from your supplier. Mine only lists "hardness", I have no idea if that is KH or GH. My hope is GH, or else my water is significantly harder than I thought...

[Stephen]

Cheers guys, I think I was starting to get it, what threw me was in the book of the test kit. It says drip the kh solution into the test water, for every drop, its 1 on the German carbonate hardness scale. So mine tested as 5. But the German hardness on the water site says 13.38. So they are 2 different, separate scales using the same name?

The German hardness scale is used to measure KH (carbonate hardness) and GH (general hardness), two different things with two different results.

The Southern Water website is telling you the water is "hard" at 13.38dGH (degrees German hardness) which is the GH (general hardness).
Your test kit is measuring the KH (carbonate hardness) and your result is 5dKH; dKH as opposed to dGH.

Basically the KH test is measuring the carbonates and bicarbonates whilst the GH test is measuring the calcium and magnesium but both use the German scale to measure the results.
In the kitchen I use a scale that measures grams, so I want 500g of flour and 200g of butter, two different things but I'm using the same scale.
KH and GH are also using the same scale but this scale does not measure grams but measures degrees of hardness (dH); so in one hand (in the kitchen) I have grams of flour and butter (500 and 200) and on the other hand (in the water) I have degrees of hardness for KH and GH (5.0 and 13.38).

I hope that makes sense

[PaulVerrall]

Cheers guys, I think I was starting to get it, what threw me was in the book of the test kit. It says drip the kh solution into the test water, for every drop, its 1 on the German carbonate hardness scale. So mine tested as 5. But the German hardness on the water site says 13.38. So they are 2 different, separate scales using the same name?

The German hardness scale is used to measure KH (carbonate hardness) and GH (general hardness), two different things with two different results.

The Southern Water website is telling you the water is "hard" at 13.38dGH (degrees German hardness) which is the GH (general hardness).
Your test kit is measuring the KH (carbonate hardness) and your result is 5dKH; dKH as opposed to dGH.

Basically the KH test is measuring the carbonates and bicarbonates whilst the GH test is measuring the calcium and magnesium but both use the German scale to measure the results.
In the kitchen I use a scale that measures grams, so I want 500g of flour and 200g of butter, two different things but I'm using the same scale.
KH and GH are also using the same scale but this scale does not measure grams but measures degrees of hardness (dH); so in one hand (in the kitchen) I have grams of flour and butter (500 and 200) and on the other hand (in the water) I have degrees of hardness for KH and GH (5.0 and 13.38).

I hope that makes sense

The flour and butter did it!
So ultimately these things aren't going to change, so it's not worth testing all that often?

[Stephen]

Cheers guys, I think I was starting to get it, what threw me was in the book of the test kit. It says drip the kh solution into the test water, for every drop, its 1 on the German carbonate hardness scale. So mine tested as 5. But the German hardness on the water site says 13.38. So they are 2 different, separate scales using the same name?

The German hardness scale is used to measure KH (carbonate hardness) and GH (general hardness), two different things with two different results.

The Southern Water website is telling you the water is "hard" at 13.38dGH (degrees German hardness) which is the GH (general hardness).
Your test kit is measuring the KH (carbonate hardness) and your result is 5dKH; dKH as opposed to dGH.

Basically the KH test is measuring the carbonates and bicarbonates whilst the GH test is measuring the calcium and magnesium but both use the German scale to measure the results.
In the kitchen I use a scale that measures grams, so I want 500g of flour and 200g of butter, two different things but I'm using the same scale.
KH and GH are also using the same scale but this scale does not measure grams but measures degrees of hardness (dH); so in one hand (in the kitchen) I have grams of flour and butter (500 and 200) and on the other hand (in the water) I have degrees of hardness for KH and GH (5.0 and 13.38).

I hope that makes sense

The flour and butter did it!
So ultimately these things aren't going to change, so it's not worth testing all that often?

If the pH drops then it may be worth measuring the KH as the KH is the biggest influence on the pH but 5dKH should provide a stable pH. Regular water changes will replenish the KH.
The GH (general hardness) should remain stable unless you intend to change it by using something like RO water (to soften the water) or crushed coral (to harden the water).
I personally measured my KH, GH and Ph so that I knew what my water was like at the start and what fish were suited to my water.
Occasionally over the years I measure the KH and GH just to confirm that no changes have taken place with the water.
It is rare for me to measure pH, KH or GH but more important to measure ammonia, nitrite and nitrate but then again I do that rarely due to experience.
On the odd occasion when a fish dies for no apparent reason then I immediately test the water; I test for ammonia, nitrite, nitrate, pH and also temperature, if those results are normal then I may test other values.
It is important to have a liquid test kit in the cupboard whether a newcomer to the hobby or if an experienced fish keeper so that you can test the water at a drop of the hat, the local LFS may not have a liquid test kit in stock and waiting 24 hours for Amazon to deliver may be a too long a wait.
I would recommend checking the dates on any liquid test kit and replace when within 6 months of the date.

As fish keepers we are better described as keepers of water. The aquarium water is where our beloved fish live, we test the pH and hardness to discover what fish are best suited to "our water" and set the temperature to the desired temperature for those fish species. We use a filter (whether internal or external) to keep the water clean and toxin free (no ammonia or nitrite) and do regular water changes. This is important as the aquarium is an enclosed environment and we do our best to manage this enclosed environment and keep the water pristine and safe for our beloved fish.
A basic knowledge of pH, GH and KH is also important as is an understanding of the nitrogen cycle (ammonia>nitrite>nitrate), equipped with this basic understanding makes us better keepers of water.

All the best

[PaulVerrall]

Cheers guys, I think I was starting to get it, what threw me was in the book of the test kit. It says drip the kh solution into the test water, for every drop, its 1 on the German carbonate hardness scale. So mine tested as 5. But the German hardness on the water site says 13.38. So they are 2 different, separate scales using the same name?

The German hardness scale is used to measure KH (carbonate hardness) and GH (general hardness), two different things with two different results.

The Southern Water website is telling you the water is "hard" at 13.38dGH (degrees German hardness) which is the GH (general hardness).
Your test kit is measuring the KH (carbonate hardness) and your result is 5dKH; dKH as opposed to dGH.

Basically the KH test is measuring the carbonates and bicarbonates whilst the GH test is measuring the calcium and magnesium but both use the German scale to measure the results.
In the kitchen I use a scale that measures grams, so I want 500g of flour and 200g of butter, two different things but I'm using the same scale.
KH and GH are also using the same scale but this scale does not measure grams but measures degrees of hardness (dH); so in one hand (in the kitchen) I have grams of flour and butter (500 and 200) and on the other hand (in the water) I have degrees of hardness for KH and GH (5.0 and 13.38).

I hope that makes sense

The flour and butter did it!
So ultimately these things aren't going to change, so it's not worth testing all that often?

If the pH drops then it may be worth measuring the KH as the KH is the biggest influence on the pH but 5dKH should provide a stable pH. Regular water changes will replenish the KH.
The GH (general hardness) should remain stable unless you intend to change it by using something like RO water (to soften the water) or crushed coral (to harden the water).
I personally measured my KH, GH and Ph so that I knew what my water was like at the start and what fish were suited to my water.
Occasionally over the years I measure the KH and GH just to confirm that no changes have taken place with the water.
It is rare for me to measure pH, KH or GH but more important to measure ammonia, nitrite and nitrate but then again I do that rarely due to experience.
On the odd occasion when a fish dies for no apparent reason then I immediately test the water; I test for ammonia, nitrite, nitrate, pH and also temperature, if those results are normal then I may test other values.
It is important to have a liquid test kit in the cupboard whether a newcomer to the hobby or if an experienced fish keeper so that you can test the water at a drop of the hat, the local LFS may not have a liquid test kit in stock and waiting 24 hours for Amazon to deliver may be a too long a wait.
I would recommend checking the dates on any liquid test kit and replace when within 6 months of the date.

As fish keepers we are better described as keepers of water. The aquarium water is where our beloved fish live, we test the pH and hardness to discover what fish are best suited to "our water" and set the temperature to the desired temperature for those fish species. We use a filter (whether internal or external) to keep the water clean and toxin free (no ammonia or nitrite) and do regular water changes. This is important as the aquarium is an enclosed environment and we do our best to manage this enclosed environment and keep the water pristine and safe for our beloved fish.
A basic knowledge of pH, GH and KH is also important as is an understanding of the nitrogen cycle (ammonia>nitrite>nitrate), equipped with this basic understanding makes us better keepers of water.

All the best

Thank you mate, I strive to learn more as a non experienced fish keeper, this helps!

[Stephen]

Thank you mate, I strive to learn more as a non experienced fish keeper, this helps!

The more we learn as non-experienced or experienced fish keepers the more interesting the hobby becomes.
I am always learning.

[KevB]

Basically you have hard but stable water that isn't likely to fluctuate in pH because the KH will keep buffering it back to whatever your reliable reading pH is (personally I wouldnt trust anything other than a properly calibrated pH meter but I'm biased as I work in a lab and have free access to such stuff). Sounds like your water is similar to mine but a bit more acidic. Mine is gH12, KH6 and pH7.2 and is very consistent whenever I've bothered to check it.

[MasonJ19]

Its true I test water from heating systems and cooling towers and install water treatment systems to them basically I test water every day of my life so fish keeping was really just a natural extension of that. I have to calibrate my pH meter every week and its surprising how quickly they can go off. Like Stephen said its as much about water keeping as it is about fish really. Everyone likes fine quality h20