API GH and KH testing liquid

[Sultrysamurai]

Hello, I am using the API GH and KH test kit with dropper and vials. 
when testing the GH I get a very faint color ch age after 3 drops. My question is do I go for a complete color change to green for my level or the level is the very faint color change to a hint of greenish?

The KH changes rather easily not the GH though.

Thanks!

[TeeJay]

That just means your at about ,a 3-4 gh. I get the same thing when I test my kh with the same kit. 3 drops just gives me a faint color change. But when I add the 4th drop it does a full bright color change.

 

[Sultrysamurai]

That’s the thing, the faint color stays faint until about 9 drops then it’s a noticeable change Vs the very slight change at 3 drops.
it’s so confusing. 

[TeeJay]

On 11/15/2022 at 9:12 PM, Sultrysamurai said:

That’s the thing, the faint color stays faint until about 9 drops then it’s a noticeable change Vs the very slight change at 3 drops.
it’s so confusing. 

Hmmm now that I'm not sure about. That it would take that many more drops to get there. 

[Marcelo]

Hi,

Only making sure … are you putting one drop, closing the tube, shaking, opening, putting another drop, closing, shaking … etc ?

Just asking because one could think you dont need to close,shake, open again ,,,

[TeeJay]

On 11/15/2022 at 10:18 PM, Marcelo said:

Hi,

Only making sure … are you putting one drop, closing the tube, shaking, opening, putting another drop, closing, shaking … etc ?

Just asking because one could think you dont need to close,shake, open again ,,,

Yes that is how I always do it. One drop close lid invert a few times and repeat.

[Pepere]

The color change is the key, not the intensity of the color.

 

the more drops you place the more intense the color is cause you are adding more color.

 

in essence the reagent reacts to the presence of gh to turn it a different color than out of the bottle.  Once all of the GH is reacted with the reagent, the solution reverts to the color out of the bottle.  More drops, more intense color.

 

at low GH it can be hard to determine color.  Looking down the hole of the tube with the tube over a white background and in good lighting helps.

 

on one shipment of fish, I tested bag water to a whopping 33 degrees of GH.  I was starting to think the solution was defective, and then it changed… and it was pretty dark color.  No doubting the change…

[Sultrysamurai]

On 11/15/2022 at 7:18 PM, Marcelo said:

Hi,

Only making sure … are you putting one drop, closing the tube, shaking, opening, putting another drop, closing, shaking … etc ?

Just asking because one could think you dont need to close,shake, open again ,,,

Yes, that is exactly how I’ve been doing it close and shake close and shake. 

On 11/16/2022 at 4:10 AM, Pepere said:

at low GH it can be hard to determine color.  Looking down the hole of the tube with the tube over a white background and in good lighting helps.

Thank you, I will try this!