API Liquid test that change beyond the specified time

CWO4GUNNER

CWO4GUNNER

USN/USCG 1974-2004 Weps
Apr 18, 2009
4,270
1
0
69
Bullhead AZ
cwo4gunnerguscgretired.blogspot.com
Most of us that have been using API liquid test kits for a long time have experienced that sometimes the color change for measuring PPM considerations of nitrate, nitrite, and ammonia will sometimes continue to slowly increase when left standing beyond the 5 minute specified time limit. Usually these increases seem to only happen just prior to a scheduled water change whereas after a water chnage the colors remain stable after the specified 5 minute time limit for as long as 24 hours.

So here is my point, do you believe that these changes where for example ammonia will read solid yellow (0PPM) at the 5 minutes time period but then change to light green 20-40 minutes later, can this be considered a more accurate reading of .25-.50 PPM? Same with Nitrite and Nitrate?

Nitrate being the more common to occasionally (not always) increase from orange withing the max 5 min specified time limit, to red 20 or so minutes later and usually just prior to a scheduled water change, this making me suspect that when these increase readings should be headed as a more accurate reading and warning. I have no evidence of this, just my conjecture. What do you folks think?
 
not sure, but when i test my tanks i always leave them after checking the 5 min time period and it never changes and they have been there for a few hours,..lol these are mostly amm nitri, ad nitrate,. and ph,.. never had a change from the 5 minute color so not real sure about but its probably something to it,. i have wondered about extra time also so i stated to leave them there to see,.
 
I've always gone by the first reading, but I know what you mean. Sometimes I do see a drastic color change maybe 10 to 20 minutes after the initial test. I have even left tests out overnight and found them to be in the much darker color ranges that indicate deadly levels. Not sure I would call those accurate.
 
It's not an accurate indication. It can indicate the presence of a smaller amount. As more time passes, the reactions continue. This means that an amount of ammonia that would not be detectable will show up. The numbers won't be right, but you will see that there is some there. The problem with this, is that there is SOME ammonia in the tank all the time, there is likely some in there air you are breathing right now. Undetectable levels are undetectable because they are too small to worry about. Your tests should be read at the specified time.

If you're tank truly had 0 ammonia, the nitrifying bacteria would die.
 
You all make a great point but I think Hebily hit it on the head for me, or hit me on the head lol:hitting:. The norm for me has been even if left overnight as sometimes I forget to rinse and put away my test tubes, that the readings dont change. But on those occasions that they do they can be considered as an increased prensence albiet inacurate, and perhaps depending upon what it is may indicate that a water change should be considered earlier rather then later.
 
Having worked at a test lab and asking that same question answer given to me was: as water sits it will off-gas changing the chemical makeup of it.The most radical of changes will happen during the first 1-4 hours. It will continue to off-gas and to absorb whatever is in the air. Testing has to be accomplished within a designated window to gain an accurate representation of the water condition in respect to potability for human consumption.

I will have to see if I can still find my chart as to what is considered as acceptable. It listed
DOC's, VOC's, Radon and other elements.
 
Everything you said really applies to water coming out of a pipe and not to an aquarium. Our systems have constant turbulence over a period of days, so they are already at equilibrium with atmospheric gases before they are sampled.
 
True, however the issue is time and adherence to manufacturer recommendation. You must have missed that. The answer is that the time as established by the manufacturer yields the best result for the application. It was also noted that longer times yields different results to which the accuracy of was questioned.

Hebily and Coach Z provided answers to the question and I provided a why longer yields a different result. The science is the same, the application is different, therefore it would be a different value only; not a different science.
 
It's only the nitrate that goes from yellow to orange after 10-15 min on me and only when I'm near the end of the test bottles. That 2nd plastic bottle of Nitrate drops is supposed to be shaken for a full minute before putting the drops in the test tube. What happens if it's not shaken each time is the concentration of the chemicals gets stronger in the bottle and leads to a darker test tube color when you get towards the end of the bottle. (I read that on some testing sight-please don't make me go find it lol). I've tested the same water with almost-gone bottles of nitrate testing liquid and brand new bottles to find out for sure. And that's what happens. Try it yourself.
 
You must log in or register to reply here.
AquariaCentral.com
Top Bottom