Accuracy of API Tests...

Discussion in 'Aquarium Water' started by Dom90, Jul 14, 2015.

  1. Dom90

    Dom90Fishlore VIPMember

    Ok so I had this strange thought. Whenever we test ammonia or nitrite, how do we actually know there is 0 ppm of ammonia or .25 ppm or whatever. What I am saying is, if you fill your test tube with the 5mL of water from a different side of the tank than your filter (assuming most of your bacteria lives in the filter and the water coming out will be ammonia-free) and that part has no ammonia. What if the molecules of ammonia are on a different side of the tank? Is it really going to be 0 ppm when you test? I'm going to use the analogy of fish. What if all the ammonia molecules are hanging out on one side of the tank, just like how some fish like to congregate on one side or another. Someone please clarify the "accuracy" of these tests, or am I just crazy? lol
  2. Geoff

    GeoffWell Known MemberMember

    Well we all know you're crazy
  3. OP

    Dom90Fishlore VIPMember

    Just a bit, but seriously I want to know if there is any logic to this...

    Are the ammonia molecules evenly spread out in a tank of water so that no matter where you grab the 5mL it will always show the same ppm of ammonia? @Jsigmo, any ideas?
    Last edited by a moderator: Jul 14, 2015
  4. junebug

    junebugFishlore LegendMember

    In a tank with sufficient filtration, there will be no readable ammonia level in any part of the tank. This is why selecting a filter with appropriate GPH for your filter type and tank size is so important in fishkeeping.
  5. hampalong

    hampalongWell Known MemberMember

    The ammonia is spread out evenly, with any kind of circulation. Logically, you couldn't have different readings if there is reasonable circulation? Besides, fish trickle out ammonia as they make it, and the filter (see junebug's post above) deals with it before it is remotely measurable by our test kits. If ammonia isn't zero, there's something wrong...

  6. OP

    Dom90Fishlore VIPMember

    Ok maybe using ammonia is a bad example. Let's go with nitrates. Are those evenly spread out as well?

    Sent from my iPhone using Fish Lore Aquarium Fish Forum
  7. CindiL

    CindiLFishlore LegendMember

    I think the answer is still yes as long as you have sufficient filtration and water movement :)
  8. OP

    Dom90Fishlore VIPMember

    Thanks for all the input, it's been bugging me for awhile to know this.

    Sent from my iPhone using Fish Lore Aquarium Fish Forum
  9. alink

    alinkWell Known MemberMember

    Think about it this way. If you dropped a drop of food coloring in your tank (dont do it), would it stay in the same spot? No, it will slowly spread throughout your tank. Within a minute or so, it would be so far dissolved that you probably wouldnt even be able to tell it was there.
  10. Jsigmo

    JsigmoWell Known MemberMember

    I agree with everyone. Normally, there is so much circulation in an aquarium that all of the various chemicals in the water are very uniformly dispersed throughout the whole thing. The filters and air bubblers stir the tank constantly.

    The food coloring method is what we call a "dye test" to determine exactly this sort of thing. This is commonly used to study flow patterns, etc.
  11. dirtmidget33

    dirtmidget33New MemberMember

    Reminds me of whenever I hear someone tell people when they take a pool sample take it further down instead of at top. If pool pump is running or people moving water around your test will show same readings anywhere in the body of water. You would be hard pressed to create such a dead spot in the water for it to actually cause a different reading.
    Some of my summer time fun is teaching people to test there pool water correctly and avoiding all the stuff pool places try to sell them.