# Help with GH & KH test



## bigstick120 (May 23, 2005)

If I recall each drop is 1 degree in 5ml of water


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## Hoppy (Dec 24, 2005)

API hardness tests give hardness in degrees, count the total drops, including the first one, to where the solution color changes. Each drop is one degree of hardness, and the sample size is 5 ml. API KH test kits seem to work pretty well, although I don't know how accurate they are. But, I have had a lot of trouble with API GH test kits. Mine have tended to never change color, and the initial color is extremely faint.


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## Left C (Nov 15, 2003)

Me too, Hoppy. I can't use API's GH test kit for the same reasons that you mentioned. Their KH test kit is easy to use.

Hagen's GH and KH test kits are easy to use. They use different reagets and you can easily tell the end points. They measure in ppm and not degrees, but you can easily do the conversion. 
GH
start: pink
end: lavender
KH
start: blue
end: yellow

Lamotte's Alkalinity test kit is very good. It has a start point, end point and past endpoint color changes that are rather abrupt for good accuracy.


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## hert1028 (Sep 9, 2013)

This is my first time using the API gh and kh test kit. Sorry but will use this old thread instead of starting a new one. 

I have no idea of reading this kit. Kh is 3 drops but it never started off blue after the 3rd drop there was a light yellow showing. Gh was 5 drops then it turned a light green. How do I read the ppm? If each drop is a degree my kh is 50ppm and my gh is 90?


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## Darkblade48 (Jan 4, 2008)

hert1028 said:


> This is my first time using the API gh and kh test kit. Sorry but will use this old thread instead of starting a new one.
> 
> I have no idea of reading this kit. Kh is 3 drops but it never started off blue after the 3rd drop there was a light yellow showing. Gh was 5 drops then it turned a light green. How do I read the ppm? If each drop is a degree my kh is 50ppm and my gh is 90?


1 German degree is equivalent to 17.86 ppm. 

For KH, as mentioned, it should go from blue to yellow. For GH, yellow to green.

Did you shake the reagent bottles very well prior to usage? Also, did you check their expiration date?


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## hert1028 (Sep 9, 2013)

I just bought it today.. I'll retest it and shake it well first.


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## PlantedRich (Jul 21, 2010)

Some depends on what you are wanting to use the info for in the long run. Do you feel you need a specific number so that you can adjust that number to an exact point? I find I only want to know if it is drifting so a general idea of staying the same or changing is all I want. For the time,effort, and money spent, plus considering how many ways the liquid tests have of being wrong, I stopped using them for GH/KH. I use test strips for a general idea and don't care about fine accuracy. 
If it is hard or soft and staying steady, that is good enough for me and I can keep the strips for much longer without them expiring.


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## hert1028 (Sep 9, 2013)

i have been keeping crs for about 6 months now and never used any kind of test kit. they all where fine up until 3 months ago. about once a week i would see 1-2 dead.


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