KH & DH tests question

[guillermops]

Hi plant gurus!

It's nice to be back here with you all I have a question regarding Aquarium Pharmaceuticals' GH&KH test kit
What colour are the liquids supposed to be?! The instructions say KH test reagent should turn from blue to yellow and GH test reagent should change from orange to green when testing. My problem is that my KH test reagent is already yellow-orange and the one for GH is already green...

Does any of you encountered the same problem? It is the second time I buy this test from different vendors and it had the same looks. Never been able to test the goddamn hardness!!

Regards

 

[nipat]

Yes, they come in those colors.

When you add the reagent into water. The color will change according to the GH/KH level.
For example, unless the water is 0 degree KH, the first drop of the KH reagent will make
the blue color.

IME with this API GH/KH kit, KH is easy, the color result is very easy to judge.
But GH is another story, the difference in color between starting point and finishing point is very subtle.
Basically, it will turn to the greenish yellow (like the color of the reagent) when it reaches finishing point.

 

[Biollante]

The Gurus Can Chime In Later...

Hi plant gurus!

Never been able to test the goddamn hardness!!

Hi Will,

There is your problem; you should be trying to find general hardness…

Perhaps you have very soft water.

Have you tried testing distilled water,

1. then distilled water with a little bit of baking soda,
   
2. another with distilled water and GH booster (a little gypsum will do),
   
3. then another with a bit of both?

It is always a good idea calibrate test sets.

Biollante

 

[DanielSev]

I have the same test kit, and the Biollante's answer is surely correct. Try to double the precision of the kit by adding drops to 10 ml of water (instead of 5 ml). Each drop represents then 0.5 dGH or dGH.

Also is good to check the manufacturing date of each bottle. Some test have a shelf life of 4 years, whereas other lasts only 3 (the GH is one of them). The number printed on each bottle represents the manufacturing date. And, yes, I have seen bottles here in Spain that were sold well beyond these 3 years shelf life (my first bottle was purchased online from a reputed store on september, 2011 and turned to be manufactured on october, 2008).

Best Regards,
Daniel

 

[guillermops]

For example, unless the water is 0 degree KH, the first drop of the KH reagent will make
the blue color.

Just to clarify, Are you saying that (in case kH is 5 degrees) the first 4 drops are going to appear blue and then the fifth one is going to turn the solution yellow again? Maybe I misunderstood the whole thing...

 

[guillermops]

Perhaps you have very soft water.
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Indeed, our water here in Madrid flows from granitic mountains...quite tasty though

 

[Biollante]

I Sound Like A Beer Commercial

Hi,

Once upon a time, I lived in a place where Bear and Elk pee were about the only constituents to the water. :cower:



It may be your test kits are accurate that is why I recommended mixing up your own water with known stuff in it.


Biollante

 

[guillermops]

Thanks, I'll do that

 

[nipat]

Just to clarify, Are you saying that (in case kH is 5 degrees) the first 4 drops are going to appear blue and then the fifth one is going to turn the solution yellow again?

Yes, exactly