Water test readings changing

[Delapool]

Hi all,

Just did a kh test and got 2. Which is possible as I have soft water but I thought what the heck, it's an easy test, I'll repeat it. Second test result was 5. I'm not game to do it a third time but will do ph tomorrow.

That got me thinking though as I almost never repeat test (it's just too much excitement). Has anyone repeat tested and have they generally had good/bad comparable results?

I've read articles that say the liquid tests are very variable and not consistent. Liquid ph vs digital ph meter I have generally found ok though. Thoughts?

 

[dalto]

I have found that the API liquid tests I use produce consistent results if the testing methodology is consistent. This mostly comes down to making sure the drop size is consistent and you are mixing it between each drop for KH/GH.

That being said, I have found the KH test to be very hard to read when KH is very low.

 

[ScotJudd]

Hi. With the API nitrate test kit great emphasis is put on the shaking of the test liquid bottles and the test tube of water being tested. This test is the most likely to vary by not following the instructions to the letter.
As a matter of course I shake all bottles a little before adding the drops to the test tube. I also ensure that the test liquid bottles are perfectly upright when counting out the drops. Bottles at a slanting angle can produce larger drops due to the increased surface area holding the liquid before it drops. This could skew the results.
As for digital Ph against liquid, I have gone for digital. Probably because I monitor the Ph more than any other parameter. I use Co2 injection and like to see the effect on Ph during the day , not every day - I'm not paranoid
And Delapool, I would repeat the tests so you then have confidence in future testing.
Happy testing !


Sent from my iPhone using Aquarium Advice