GH + KH Test Kit Help

So my test kit arrived this morning for GH and KH. I've never actually tested the hardness of my water until now. Iv'e just tested my tank water and I need help with the results so I can try and understand how this works haha.

For KH I needed 3 drops to change the colour in the test tube, and as for GH I needed 5 drops to change the colour. Now my main question is what number do I need to get the actual results into ppm? I'm assuming I multiply the number of drops with another number that I'm missing? Sorry if this seems silly to be asking but the instructions just aren't doing it for me haha. If anybody could dumb this down to me id appreciate it haha.

Cheers

 

well: there will be a table or 'formula' in the kit instructions.

also there might be a diferente 'sensitivity setup': in mine it is 10 or 5 ml. if you collect 10ml you divide the number of drop per two in the calculation...

 

If you have the API test, the conversion chart is in the manual.
3 drops - 53.7 ppm
5 drops - 89.5 ppm
Same for KH and GH.

 

Arrrgh yep found it haha, sorry guys. 17.9 was the number I was after and yes its an API test. Thanks heaps!

 

well... I think 17.9 is the 'magic number'

mine is a brazilian made test and is exact the same.

you can have a better 'resolution' if you double the water and divide the drops by 2. the vial that comes in my kit have a 5ml and a 10ml line for that purpose.

 

This is a very helpful thread, at least for my ego. I had trouble as well with the API "instructions" - as to whether the drop-values should be interpreted identically for KH/GH. Piaelliott's comment is the conclusion I came to but it was hard. API support was not helpful. And once upon a time I was a chemistry major ... so thanks all!