GH help wanted.

aqualung

Junior Poster
Jan 24, 2005
11
0
1
Test kit reads GH of 6 (107 ppm)

Professional lab reports:

Calcium 36 mg/L
Magnesium 9 mg/L
Sodium 34 mg/L

When I add these up (include Sodium??) I get 79 mg/L

Something does not add up. Anyone, please share your thoughts. :confused:
 

m lemay

Prolific Poster
Jan 23, 2005
60
0
6
CT
Re: GH help wanted.

Theres a lot of potential variables here. Is the lab report from the exact same water sample from the same time? If not, your comparing apples and oranges.
 

aqualung

Junior Poster
Jan 24, 2005
11
0
1
Re: GH help wanted.

m lemay said:
Theres a lot of potential variables here. Is the lab report from the exact same water sample from the same time? If not, your comparing apples and oranges.

No, the lab report was from water I drew from the well towards the end of December, and I did not test that sample myself.

You mentioned other variables. Can you or anyone else think of a few other ones?
 

baruch mor

Prolific Poster
Jan 23, 2005
30
0
6
Re: GH help wanted.

i would guess that the "aquarium" test kit is not accurate as the lab test. its about 25% difference - u should take into consideration that u can always get 5% error from each test kit , specially "aquarium" test kits ...
 

aqualung

Junior Poster
Jan 24, 2005
11
0
1
Re: GH help wanted.

I just found what I wanted on The Krib:

1dGH = 7.143 ppm Ca2+ ....so....

36 mg/L Calcium ÷ 7.143 = 5dH

So my hobby-grade test kit turned green after 6 drops, that's close enough. All is right with the world.