Ammonia False Positive? (api Master Test Kit)

Discussion in 'Test Kits' started by BloonStuff, Jun 14, 2018.

  1. BloonStuffValued MemberMember

    Hi again, lol.

    I'm just wondering if a false postive for ammonia is much of a thing with the API Master Test Kit because the other day I accidentally dosed my tank up to 8ppm+ ammonia and the next day it was down to about .50ppm or so. I was shocked tbh. However, for some reason I can't seem to get a reading below .25ppm. Like surely if it can go from 8ppm+ down so much in 22 hours then it should be able to go from .75ppm to 0ppm in 24 hours?

    So I'm just wondering if it's possible I'm getting a false positive? Does that sound reasonable?

  2. Floundering_AroundWell Known MemberMember

    Have you tested your nitrites and nitrates? High levels of either of them can stall the bacteria from breaking down more ammonia
  3. AdriifuWell Known MemberMember

  4. BloonStuffValued MemberMember

    Oh, sorry. I should have included those. Yes, I tested them.

    So earlier in the week my nitrites and nitrates disappeared and were both at 0ppm. My ammonia was still .25ppm and it was suggested that perhaps the small bioload and the plants are taking care of the nitrates and that my tank might be almost cycled. I did a water change then to clean the tank up and after that, that's when I accidentally dosed it up to 8ppm+ and then the next day it was back down to .50ppm and the nitrites had gone back up to .50ppm and the nitrates were 5ppm. The next day I tested again and the ammonia was down to .25ppm and so were the nitrites and I didn't test the nitrates. I dosed the ammonia back up to .75ppm.

    That leads me to today and the ammonia being back down to .25ppm, the nitrites weren't quite .25ppm but they weren't 0ppm either. I'd say maybe .10pm or so. Nitrates were back down to 0ppm. The tank is only a 5 gallon and there's a number of plants and a lot of algae in it.
  5. AdriifuWell Known MemberMember

    Nitrates were most likely consumed by your plants and algae unless you've performed a water change recently. Not a big deal. They'll come back. It seems as though your tank is nearly cycled. Just a week or two and you'll be good.
  6. BloonStuffValued MemberMember

    'Kay, thanks. :) Is it normal that 8ppm+ can drop down to .50ppm in 24 hours but .50ppm can't drop down to 0ppm in 24 hours?
  7. RtessyFishlore VIPMember

    Try testing half distilled and half tank water, and if you get an ammonia reading try testing just the distilled water. If there's still ammonia detected, it's likely a kit error
  8. AdriifuWell Known MemberMember

    It can happen. That was a lot of ammonia for the bacteria to break down. However, it could also be test kit mistake.
  9. cla001Valued MemberMember

    I second testing distilled water side-by-side with your water. I have been doing so many tests with API kit over the last 6 months that I feel like most of the time I can tell the concentration even without looking at the chart, but difference between 0 ppm and 0.25ppm ammonia is still one of the few things that I struggle with using the kit. I actually did a distilled water test a few times trying to make sure it was actually 0 and not more.

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