Test Kits Now Showing Strange Colours!

[jnms]

This is a pretty weird one. I am just coming into the third week of a fishless cycle. I have been testing for ammonia and nitrites everyday, and nitrates every few days.

Now suddenly today, the nitrite and nitrate test kits are showing strange colours. I have the Nutrafin Mini Master test kit. Both the nitrite and nitrate tests are meant to turn the water shades of purple. When I first put in the drops of reagent that is exactly what happens - however with these test I have to wait a few minutes before taking the readings.

By this time the nitrite test turns a bronze yellow - whilst the nitrate test turns a pinkish red. They have never done this until today.

I tested the kits on plain tap water - and they work exactly as they should. So I know the test kits haven't suddenly gone funny.

What could be doing this??

 

[Ludwig Venter]

As a routine duty in my natural earn a living job,... we do water tests for all sorts of pollutants and subsequently get about 17 to 24 different qualities of the waters that we test using various techniques by using precision instrumentation and the like, but even so, testing one batch of samples twice brings up such a variation in results, that (even I) are doubting the results... (it is costing us thousands to "accurately" obtain one set of readings)..... Let alone the results obtained from a 10/15$ test kit???.....

 

[jnms]

As a routine duty in my natural earn a living job,... we do water tests for all sorts of pollutants and subsequently get about 17 to 24 different qualities of the waters that we test using various techniques by using precision instrumentation and the like, but even so, testing one batch of samples twice brings up such a variation in results, that (even I) are doubting the results... (it is costing us thousands to "accurately" obtain one set of readings)..... Let alone the results obtained from a 10/15$ test kit???.....

Ok I tested the water three times tonight and each time the test water turns yellow. It is meant to turn purple, there is no yellow on the chart. Prior to tonight it has always been a shade of purple.

So what you are suggesting is there is nothing wrong with my water - or at the very least there is no true way of me knowing what is going on?

 

[Ludwig Venter]

Is there any expiery date on your test kit??.....

 

[kadkins20]

something sticks to the inside of my test tubes after im done using them, so one day i decided to clean them with a q-tip after washing them with water and i stripped off a lot of purples and yellows and oranges

its possible that your test tubes could be mucking up the experiments. Try cleaning them thoroughly and see if that helps

 

[jnms]

something sticks to the inside of my test tubes after im done using them, so one day i decided to clean them with a q-tip after washing them with water and i stripped off a lot of purples and yellows and oranges

its possible that your test tubes could be mucking up the experiments. Try cleaning them thoroughly and see if that helps

Thanks for this suggestion! I just unsealed an unused test tube, and the test seems to work fine. However with the Nitrate test - it still goes slightly off colour, but this is once the water has been in the tube for 10+ minutes...which isn't what these tests are designed for. Even still - does this sound normal?

 

[kadkins20]

i dont think ive ever had my tests go way off color, but they do tend to change if u leave them for too long

than again, the nitrate one does require you to mix two chemicals... theyre probably fairly unstable when mixed, so its not beyond reason that they would go off-color if left for too long

i'd say its normal. Just make sure the tubes are well cleaned before you do more tests

 

[jnms]

Right, seems that even though I have thoroughly cleaned all the test tubes (including the new ones) the tests are still turning yellow instead of purple!

I suddenly remembered that I added 10litres of dechlorinated water into the tank about 3 days ago. When I put the water into the tank I thought it odd as a bunch of small bubbles floated around the surface of the water for 10 - 15 mins before finally dissipating.

I am convinced something isn't right here because the tests never used to act in this way...

 

[tyyrlym]

My API high range pH test does this from time to time. The color goes right off the charts to a dark, dark purple. I just rinse the test tube out good, let it dry, and try again. Most of the time it works just fine afterwards. Some chemicals remaining in the tube is about the only answer I've got to why it happens.

 

[jnms]

The problem seems to be that somehow 'something' has gotten into my tank. I have a feeling that when I left that 10litre bucket of water to stand, my 2 year old daughter dumped something in there. I have a sneaky feeling she may have washed soap off her hands into it...

So taking this theory, I filled a test tube with 2ml of tank water (instead of 5ml) and then added 3ml of tap water. I redid the tests and they came up perfect!

It certainly looks like some sort of 'gunk' got in the tank. I did a 33% water change, and that appears to have helped a lot. But it looks like I will need to do a 10% water change for the next few days.

How much is this likely to set the cycling back by?