gH & kH question

[MightyWarMonger]

Ok I have a gH & kH test kit and acording to the instructions to mesure the gH & kH it's how many drops it takes to change it from one color to the other. In my tank it takes 6 drops for both to change witch makes it 125.3 ppm on both as per the chat in the instructions I think unless I read them wrong (witch is not suprising). But when I see every one else refer to it they say 8 or 13 or some other number like that are they refering to haow many drops it takes to get there results or am I totaly off the chart on this one. I read the directions twice, also I dont even know what the corect hardness for cichlids is (I have a mixed tank). I know/think some like it hard but how hard? or am I wrong on that to? any help is apreciated.

 

[Cory Keeper]

they are more than likely using the german measurment, I forget the name of it. You are listing it in the US form, PPM or Parts Per Million. 125 makes it about midway, borderline soft. Research the Chichlids you have in your tank and if they need harder water add some crushed coral accordingly. liquid calcium may also work.

 

[Star_Rider]

1 is PPM the other is degree's hardness
0 - 4 dH, 0 - 70 ppm : very soft
4 - 8 dH, 70 - 140 ppm : soft
8 - 12 dH, 140 - 210 ppm : medium hard
12 - 18 dH, 210 - 320 ppm : fairly hard
18 - 30 dH, 320 - 530 ppm : hard
higher : liquid rock

 

[MightyWarMonger]

awsome thanks

 

[DarkSoul]

multiply GH by 17 to convert it to ppm, and KH by 17.9 to get ppm.

 

[nickmcmechan]

what sort of cichlids?

 

[jpappy789]

2 yellow labs, 1 Nimbochromis livingstonni, 1 Metriaclima lombardoi,

1 Pseudotropheus sp. Acei (Ngara) 1 Otopharynx lithobates X Sciaenochromis fryeri hybrid 3 frontosas

^From their sig. I would think they would be happier with harder water, but my guess is that they are locally bred/raised so it might not be essential for their survival.
​

 

[MightyWarMonger]

2 yellow labs, 1 Nimbochromis livingstonni, 1 Metriaclima lombardoi,

1 Pseudotropheus sp. Acei (Ngara) 1 Otopharynx lithobates X Sciaenochromis fryeri hybrid 3 frontosas​

^From their sig. I would think they would be happier with harder water, but my guess is that they are locally bred/raised so it might not be essential for their survival. ​

verry sharp........ I got them mostly from a chain LFS so no idea were they were bread but they are all juviniles. I will see if I can rais the hardness

 

[NewObsession]

I know what pH is, but outof curiousity ..what is kH and gH?

 

[Esox lucius]

There are different hardnesses;
- Carbonate Hardness (aka - Alkalinity, Buffering Capacity or KH) which is actually a measure of mostly bicarbonate, 1dKH = 17.86mg/L CaCO3 which means that it would take 17.86mg/l of calcium carbonate to increase the alkalinity of the water by 1dKH this is the same for general hardness except it is measured in dGH instead of dKH.
- or general hardness (GH) which is the measure of Calcium and magnesium either mg/L as calcium carbonate(CaCO3) or in German degrees (dGH).
- or just Calcium (Ca2+).
- alternatively their is Calcium Hardness which is also measured in mg/L as calcium carbonate(CaCO3).

General hardness (GH) is usually measured in dGH (German degrees) to convert this to mg/l (or ppm) multiply your dGH by 17.86
Calcium hardness (CH) is Calcium (Ca2+) in mg/L multiplied by 2.5

To work out your magnesium levels (Mg2+) take the general hardness (GH) in mg/L (CaCO3) minus Calcium hardness in mg/L (CaCO3)which equals magnesium hardness and then divide by 4.1

The hardnesses which most people test for with freshwater are general hardness and carbonate hardness.

Everything in the aquarium tends to effect hardness even bacteria, somethings more than others. There are ways of lowering your hardness or increasing it depending on what species you want to keep.

You can use RO water and mix with tap water for soft water tanks to get the desired hardness level and use substrates (bogwood, peat etc) that will leak small amounts of acidic material over time which dissolves the calcium and magnesium in the water causing it to become softer.

Certain rocks can contain large amounts of calcium and magnesium, this can be tested by doing the vinegar fizz test with rocks prior to putting them in the tank if it fizzes then it is likely to contain a fair amount of calcium and magnesium (remember to wash vinegar off before placing in your aquarium), which will increase hardness over time.

Increasing and lowering hardness can have an effect on pH so if you do decide to increase or decrease hardness make sure to measure your pH at the same time.

Most fishes will be ok with an increase or decrease in hardness as long as it isn't a sudden change.


Phil