# Test kit calibration standards



## dennis (Mar 1, 2004)

Hi all,

Recent posts have caused mt to wonder just how accurate my kits are. Even kH kits, which I always figured to be a simple test with little chance of error, can be way off. Hopefully this thread will help others make sure their readings are not too faulty.

Please post to this thread any and all kit calibration tests one can easily do using everyday stuff.

Example: How much baking soda, NaHCO3, should be added to a sealed gallon jug of distilled water(available at any grocery store) to achieve x degrees for the standard 5ml test kit sample?

Useful test standards would be:

KH
GH
pH
NO3
PO4
Ca

Also, is there a way to re-use the first standard, such as useing the gallon of H2O with baking soda in it to also test for NO3, by adding x amount of KNO3, or PO4 by adding Fleet enema or KH2PO4, etc?

Creating the standards using grams of x compound would be best, IMO

Thanks for all your help


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## Laith (Sep 4, 2004)

For NO3:

- Mix 4.1g of KNO3 in 500ml of RO water.
- 1ml of this solution in 1l of RO water should give you 5.03mg/l of NO3...

For example, 4ml of the initial mix in 1l of RO water should give you 20.12mg/l of NO3.

I use this regularly and find that my JBL NO3 test kit is spot on, even better than my LaMotte kit. This test also keeps me from purchasing Hanna's NO3 colorimeter!  

It is always better to use RO or distilled water for this type of testing.

And if you're going to be sensible and use grams, you might as well be sensible and use liters and ml as well!  
(couldn't resist there...  ).


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## Laith (Sep 4, 2004)

I know most people don't trust Fe kits. Here's a test to validate (or not) your assumptions:

For Fe:

- 1ml of Flourish + 99ml of RO water = 100ml total.
- 1.25ml of this solution in 200ml of RO water should give you 0.2mg/l of Fe.

Surprisingly, my Fe test kit seems to work well!


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## dennis (Mar 1, 2004)

Laith said:


> And if you're going to be sensible and use grams, you might as well be sensible and use liters and ml as well!
> (couldn't resist there...  ).


 Laith, thanks for the standards. Hopefully folks will keep adding more and we can all chaeck each others math (well, not me, I am bad at math)

As for using liters and milliliters, I planed on it. I also am one of the few people I know with a fyull set of beakers, flasks, graduated cylinders and other lab grade equipment. I figured most people had cooking measuring cups, gallon jugs of DI water and Dasani water bottles. Unfortunately, this side of the pond, we get things measured in ounces and gallons. For instance, a Dasani water bottle contains 591 ml, a Nyquil bottle has 291ml and peroxide comes in a bottle with 947ml. All those convert to even numbers using ounces though](*,)


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## Laith (Sep 4, 2004)

Ok, I'll be nice  :

1l is equivalent to 0.264 gallons US.
Therefore 500ml (1/2 of a liter) is 0.132 gallons US.
100ml is equivalent to 3.38oz or 0.21pint.
1ml of Flourish is equivalent to 1 thread on the Flourish cap (not on the 1l and 2l Flourish bottles though).

And, for our purposes, mg/l is the same as ppm...


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## Mortadelo (Mar 14, 2004)

Maybe we could use bottled water for test calibration as long as there are no or little seasonal quality changes. Some bottles display bicarbonate content among other values. And some brands even offer more complete analisys on their website. Dunno, just a thought.


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