If you get a wacky test result then test again

[PedroYoung]

This morning I was doing my weekly water tests and my PO4 came back at 0.37 on my Hanna HI713 phosphate checker. Woah!! I normally run between 0.05 and 0.1 which is where my corals seem happiest. I start immediately thinking "I've been out of town, my wife has been feeding, get a huge water change ready!!!". Then I thought "wait, if anything she prob forgot a feeding" so I fired up another sample and ran a second test. Came back 0.07, right in line with normal. Just to be safe I ran a third and it came back 0.07. I am not writing this post to rant about inaccurate tests or anything, just a simple concept I've been trying to use myself "If a test seems wacky, test again before taking action". Seems like common sense, but we sometimes feel like these tests, which are just "hobby grade" are infallible. They aren't. It can be user error (not getting all the reagent in the vial, smudge on the vial, bad zero cal, etc) or could just be a gremlin, but my advice is take the time to run another test.

 

[Auquanut]

I've done the same thing myself. I get a wonky reading and immediately freak out about equipment malfunction or whatever, and what to do to fix it before reality kicks in and I retest.

 

[LobsterOfJustice]

Always a good reminder.

You also did the right thing by testing multiple times to invalidate a previous unexpected result. You shouldn’t just test twice and then pick the one you like more - what’s to say the first one wasn’t right and the second one wrong? You should require 2-3 similar expected results to invalidate your first.