Finding it hard to test GH and KH

[TomNS]

Hi guys,

Please excuse my ignorance but I am finding the instructions for my GH and kH test kit hard to follow.

I have the "master test kit" which all number of test but I have never been able to get the GH or KH to work.

For the Gh I take the required water - start putting drops into it and it never changes from orange to green. I have put in 90 drops and filled the little tube and it makes no difference am I supposed to invert the little test tube after every drop ? what is the trick ? I am trying to get an idea of what it should be so I can change it for my discus - I am in brisbane so I don't know if it has hard or soft water to being with

Where am I going wrong ?

Cheers
Tom

[dcarmau]

you're supposed to shake the tube after each addition... Or at least you are with my kH/gH test kit...

hope that helps!
Dylan

[lesley]

when you put the first drop in, do you start off with the colour that is mentioned in the kit?

you do need to cap and shake after each drop.

if you do not get the initial colour then there is no general hardness at all!

if you do get that initial colour, then all the additional drops are not changing the water, I don't think I can suggest anything other than your water must be incredibly hard!

maybe someone else has some helpful suggestions?

[lesley]

when you put the first drop in, do you start off with the colour that is mentioned in the kit?

you do need to cap and shake after each drop.

if you do not get the initial colour then there is no general hardness at all!

if you do get that initial colour, then all the additional drops are not changing the water, I don't think I can suggest anything other than your water must be incredibly hard!

maybe someone else has some helpful suggestions?

[TomNS]

The initial colour is orange and it is supposed to change to green

1 drop does give me the initial however I will try again with a cap invert between each individual drop


Thanks
Tom

[Discus Tribe]

Im having the same problem.
Test kit does not say to shake nor comes with a cap but have tried shaking too.
It says to add drop by drop till the water turns from red to green (1 drop equals 1GH) but the liquid in the bottle is green and does not turn red at all just stays green with every drop. Im assuming my water has 0GH is this possible? PH stays around 6.6-6.8 im from cairns if anyone else knows the actual hardness of cairns water that would be great!

[holotype]

To determine low values for kH & gH, simply dilute the sample by twice or four times the measured amount, then divide the added drops by either half or a quarter. This will allow you to see fractional values.

For example in my tank the kH is 1.75, determined from adding seven drops to a 20ml sample. With a 5ml sample the colour changed from blue to yellow on the second drop, hardly an accurate reading. Higher dilution allows you to more closely observe the change through the colours. With a 20ml sample tested for kH, it clearly passes from blue to green then to yellow, at which point the value can be more accurately determined.

If you don't think the test kit is working check its age, (and stating what brand it is would help), many reagents will degrade over time, especially if exposed to heat, sunlight or if left with the cap off.

[Bad Inferno]

holotype
I was thinking somebody must make a KH kit better than a 1 deg resolution....Great post with just increasing the sample qty....

cheers rob