Something wrong with not one, but two hardness test kits?

[ralliart12]

Previously (a few months ago) I was using the KH & GH test kits from API (as seen below; it's this green packaging though, not the more "common" API blue packaging) to test the hardness of the tap water from my office. Despite following the instructions carefully, i.e. drop-by-drop & shaking the solutions between each drop, the colour transition that were expected from both tests, did not occur (after my drops). At the time, I assumed the test kits were probably expired.



Recently I bought another set of test kits from Sera (KH & GH again); to test the tapwater in my house. Once again, the colour transition that were expected to occur, did not manifest after many, many drops. For the KH test, there was no transition from blue, via green, to yellow. The test solution was already orange in colour when the 1st drop hits the tapwater (there was no "blue" to start with). For the GH test, there was no transition from red, via brown, to green. The test solution was already green in colour when the 1st drop hits the tapwater (there was no "red" to start with).

I stopped dripping the test solutions in either tests when the 10th drop as administered as I don't expect any changes to occur. Video as follows (the recording is colour-corrected):



Can anybody tell me what's going on? The local tap water cannot be so hard as to require more than 20 drops to demonstrate a colour-change right?

[stormhawk]

I had the same weird results with my tap water as well but there was a faint color change after awhile. I did the same test with Fiji Water and got a reaction after several drops too.

I believe the Sera test kits are not that sensitive. However I noticed, at least for my tap water, that GH is roughly 4-5 and KH is only 1 or 2. Which is quite low.

[Shadow]

Singapore kH is low, it probably change to yellow after 1 drop. You can add baking powder to cup of water and test it. This is to test whether the kH test working or not. It should turn to green/blue (can't remember what color) after fist drop.

[ralliart12]

So what can I do if I truly want to measure the hardness of my tap water? Get a third test kit (after API & Sera, I only saw the $31.50 kit by Tetra)? I regularly see folks posting (low) values of GH/KH values of their tank water, what test kits are they using? Cannot be the tap water from my house so special right? i.e. no hardness from minerals.

[felix_fx2]

Ralliart12, baking soda will make water hard. For you to reference the reaction of the test kit.
Edit: I'm using sera. Bought them to make d4kh solution for drop checker. Less then $15 for the kh

[icefire]

i have only hardness test kit by Sera and its still working perfectly.. just that it takes more than 10 drops lol....

[ralliart12]

@Everybody

Before we proceed any further, is the "starting" colour (straight from the dropper) of both my GH & KH test solutions, the correct color?

Because if the liquid straight from the eye-dropper bottles is even wrongly-coloured to begin with, then there's nothing further to test.

I had the same weird results with my tap water as well but there was a faint color change after awhile...

You mean like "drip 1 drop, shake, then wait a minute" before deciding whether to proceed with the next drop?

...I did the same test with Fiji Water and got a reaction after several drops too...

What's "Fiji water", if I may ask?

...I believe the Sera test kits are not that sensitive. However I noticed, at least for my tap water, that GH is roughly 4-5 and KH is only 1 or 2. Which is quite low.

Besides Sera & API, the only other brand that I saw is "Tetra". Im slightly inclined against buying a 3rd kit just to "try my luck". Or are there more reliable ways to measure hardness instead of relying on test solutions?
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Singapore kH is low, it probably change to yellow after 1 drop. You can add baking powder to cup of water and test it. This is to test whether the kH test working or not. It should turn to green/blue (can't remember what color) after fist drop.

Ralliart12, baking soda will make water hard. For you to reference the reaction of the test kit...

@Shadow @felix

Okay, I'll grab some generic baking soda & test, but testing using which kit? The KH or GH one?
*

...Edit: I'm using sera. Bought them to make d4kh solution for drop checker. Less then $15 for the kh

@felix, have you tried testing your tap water using your Sera test kits?

Btw, since you have the same brand, may I verify with if the colour if the solution from my test kits, are correct (as seen from the video)?

i have only hardness test kit by Sera and its still working perfectly.. just that it takes more than 10 drops lol....

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May I know the GH & KH value of your tap water?

[wongce]

Bro, from your video at 3 mins (Sera GH)... the first drop is red/orange... then the second drop it becomes green.... it shows your GH is around 2...( i have the same test kit) the first drop is harder to spot as the orange tint is very slight... your tap water is good...

The GH of tap water around my wululand area differs from 2 to 4...I tested few times and seldom test not as i got bored of it...LOL (I am not keeping GH sensitive shrimp though)

[cheetf]

Try to use 10ml of water and test. Every 2 drops should be 1 degree. I find it much easier to see.

[stormhawk]

Fiji Water is a brand of bottled water that is fairly alkaline in nature.

I just follow the instructions and drip in 1 drop in 5 ml of the tank water, shake then drop another. I do this until a color change is noticeable. Mineral content in our tap water is variable.

[felix_fx2]

Never tested tap water yet.

[VSGenesis]

I was curious and did a test using API. The blue box series.

On the left is GH and on the right KH
Picture 1 shows one drop
Picture 2 GH turns from orange to green; KH from blue to yellow/orange

Result GH 3; KH 2. I can do another test again if you want.

PS: Sengkang Water. =P