Despite API reputation, the Chemicals in the test kits are actually good

[brandon429]

Based on your work, if we update the procedure and method the actual kit is strong, agreed. Api why have you delayed even one microsecond implementing a new instruction kit with a usage and context addendum for the readout

An updated usage packet with context info and confounds to avoid could streamline results much stronger + increases buyer brand quality association. Moving past 'must be zero to be safe' is the number one stricken clause in the new set

Considering the degree of doubt api has created in the ammonia test will the same instruction set since 1982, the undoing is simple, sell this to them as an addendum to or a new instruction set for the kit

they owe you for showing a method to streamline results/ social media big money/ they owe you a chunk. This thread shows its potential when the right order of ops plus reader ruleset is applied

 

[taricha]

I’d be much more interested in alkalinity and calcium though. In nearly 18 years and more than a few dozen tanks setup, I’ve never once tested ammonia or nitrite.

Here's a look at API alkalinity.

I did two API kits and my Red sea kit and ran them each as though a 10mL sample (so 2x the API drops of a 5mL sample).
In each case I added (to distilled water) the amount of those alk reagents that would give you a certain dKH and then titrated with 0.100 Molar NaOH until I got the color change endpoint (a green like on the Red Sea color card).

The two API kits were essentially identical and about 10% off from my Red Sea kit.
The black line represents the theoretical correct value of 1 meq/L = 2.8 dKH.
(I don't know why all the kits were that far off from theory, but I'll check my NaOH stock later.)

Anyway, looks like both the API kits give me something quite close to my Red Sea kit.

 

[PeterErc]

Thanks for doing this, I have used API for years. A 5ml syringe for samples and all is good.
Keep it Simple. I have one of those checkers for PO4. If ALK and CA are the same process then f that. API all day.
The Nitrate and I believe Ammonia kit can be used with 2.5ml sample water and half the reagents. Maybe some others but I mostly use alkalinity and calcium. Would be nice for a magnesium kit from API, although I don’t test too often.

For me I just have to be close, if alkalinity is low calcium probably is too. An extra scoop of kalkwasser in the top off bucket. If nitrate is creeping up, some vinegar in the top off. If phosphate creeps up some lanthanum in the overflow. If nutrients are too low (never a problem) feed fish more. Every blue moon I bump the magnesium, use NSW so that’s not usually an issue.

 

[taricha]

you're right, @PeterErc stability is about tracking the trend - day to day and week to week. All you need is a kit that's decently close and will be very repeatable. API alk can do that, and you're also right that it's easier to catch a change in calcification by looking at Alk trend and not Ca.

 

[MnFish1]

Here's a look at API alkalinity.

I did two API kits and my Red sea kit and ran them each as though a 10mL sample (so 2x the API drops of a 5mL sample).
In each case I added (to distilled water) the amount of those alk reagents that would give you a certain dKH and then titrated with 0.100 Molar NaOH until I got the color change endpoint (a green like on the Red Sea color card).

The two API kits were essentially identical and about 10% off from my Red Sea kit.
The black line represents the theoretical correct value of 1 meq/L = 2.8 dKH.
(I don't know why all the kits were that far off from theory, but I'll check my NaOH stock later.)

Anyway, looks like both the API kits give me something quite close to my Red Sea kit.

Curious - did you do more than 1 RedSea test?

 

[MnFish1]

The big problem I think people are having with API, though some readings are sky high (of ammonia) - I have not heard reports of 'low ammonia' when tested. From my readings MOST of the API tests are called out for reading a 0.25 level of total ammonia. IMHO - the reason for this is people don't realize that with these kits (ammonia) - you're not supposed to average visually the results. You're supposed to pick the color closest to the chart - and thats the numbers. i.e. a slightly green ammonia is read as 0. A green closer to .25 is read as .25.

From API: "

1. Read the test results by comparing the color of
   the solution to the appropriate Ammonia Color Card (choose either Freshwater or Saltwater. For ponds, use the freshwater color card). The tube should be viewed in a well-lit area against the white area of the card. The closest match indicates the ppm (mg/L) of ammonia in the water sample. Rinse the test tube with clean water after use. Note: Do not pour test tube contents back into the aquarium/pond."

 

[taricha]

I re-checked this:

The two API kits were essentially identical and about 10% off from my Red Sea kit.
The black line represents the theoretical correct value of 1 meq/L = 2.8 dKH.
(I don't know why all the kits were that far off from theory, but I'll check my NaOH stock later.)

My Hach 1.00N NaOH exactly balances an equal volume of my Hach 1.0N HCl, so the standards are likely fine.
And using the NaOH standard I confirmed that a redo gave me the same result as in the above chart.

Here's the same data but flipped around and done in terms of just dKH to make it a little easier to interpret.

So an actual alkalinity of 8 kH would be measured at about 7 on my Red Sea kit, and 6-6.5 on my two API kits.

Some people may decide that's close enough. Others may not like that performance.
(in Randy's alkalinity standard thread, Red Sea was also measured there to give a result of 7 for an alk standard of 8 dKH.)

 

[MnFish1]

I re-checked this:



My Hach 1.00N NaOH exactly balances an equal volume of my Hach 1.0N HCl, so the standards are likely fine.
And using the NaOH standard I confirmed that a redo gave me the same result as in the above chart.

Here's the same data but flipped around and done in terms of just dKH to make it a little easier to interpret.

So an actual alkalinity of 8 kH would be measured at about 7 on my Red Sea kit, and 6-6.5 on my two API kits.

Some people may decide that's close enough. Others may not like that performance.
(in Randy's alkalinity standard thread, Red Sea was also measured there to give a result of 7 for an alk standard of 8 dKH.)

I personally would not think it's close enough. - however I would also be doing multiple measures with mean and standard deviations - and then measuring whether the differences were within statistical significance? The interesting thing is that neither test matches well, the stock - but unknown whether its significantly different

 

[Dan_P]

I re-checked this:



My Hach 1.00N NaOH exactly balances an equal volume of my Hach 1.0N HCl, so the standards are likely fine.
And using the NaOH standard I confirmed that a redo gave me the same result as in the above chart.

Here's the same data but flipped around and done in terms of just dKH to make it a little easier to interpret.

So an actual alkalinity of 8 kH would be measured at about 7 on my Red Sea kit, and 6-6.5 on my two API kits.

Some people may decide that's close enough. Others may not like that performance.
(in Randy's alkalinity standard thread, Red Sea was also measured there to give a result of 7 for an alk standard of 8 dKH.)

This work leads to question that haunts (?) the hobby. How close is close enough, and how much variation in the measurement is acceptable? The answer should lead us to keep livestock healthy and at a reasonable cost, i.e., just enough accuracy and precision. Is there a scientifically based answer? My guess at the answer, based on the fact most aquarist do not test replicate samples, use a chemical standard to validate the test method each time, nor know the accuracy and precision of the analytical method, is that quite a bit of leeway exists for the consistency of the analyte level and the true concentration. Thoughts?

 

[Seansea]

I use api for nitrate. Took a reading on the day i sent my icp test in. I had it at 2. Icp came back 1.9. Is that close enough?

 

[calhoun3186]

Very good research and write up. I really appreciate your use of applicable and appropriately applied statistical methods. Impressive.

 

[taricha]

This work leads to question that haunts (?) the hobby. How close is close enough, and how much variation in the measurement is acceptable? The answer should lead us to keep livestock healthy and at a reasonable cost, i.e., just enough accuracy and precision. Is there a scientifically based answer? My guess at the answer, based on the fact most aquarist do not test replicate samples, use a chemical standard to validate the test method each time, nor know the accuracy and precision of the analytical method, is that quite a bit of leeway exists for the consistency of the analyte level and the true concentration. Thoughts?

I've thought about this occasionally. When you ask large groups of R2R people about their alkalinity, you get these really cleanly normal distribution curves like this....

And this one's even better...

That's an amazingly smooth bell curve! Why?

My guess is that it means that in the context of hobby reefkeeping, the actual alkalinity doesn't really matter - within the broad agreement that 7 to 9.5 is the target. Also that so many people have a clear answer means that they have a number they like and they aim for it consistently. And their tank likes this consistent target more than experimentation.
I've never heard a reefer say "my tank really loves a swing up and down from 7 dKH to 10."

We could wonder to ourselves if everyone used a kit calibrated against lab standards, and charted their rate of coral growth by mass or length/month maybe the normal distribution wouldn't look like that - maybe it'd be skewed narrowly toward an actual "best" value.
But since that's not the hobby situation, my interpretation of this chart is that it's just a vote for consistency aiming at a widely agreed target giving good results.

(feel free to make up your own stories about these charts )

 

[taricha]

I use api for nitrate. Took a reading on the day i sent my icp test in. I had it at 2. Icp came back 1.9. Is that close enough?

I'll still use my hanna or Red Sea as go-to NO3 but I'd be happy with those numbers.

 

[Randy Holmes-Farley]

I'll still use my hanna or Red Sea as go-to NO3 but I'd be happy with those numbers.

I think this dilbert might also be appropriate... lol

https://www.random.org/analysis/dilbert.jpg

 

[Seansea]

Wont argue hannah is easier and the digital is nice. I use the alk checker which i won on the cherry coral sale. But at 10 bucks i can buy six api nitrate test kits for 1 hannah checker. Thats 6 years worth of api nitrate tests.

 

[Red2143]

I use api for nitrate. Took a reading on the day i sent my icp test in. I had it at 2. Icp came back 1.9. Is that close enough?

How do you know your api nitrate was 2 based on the color?

 

[A_Blind_Reefer]

I can’t wait twenty years to see your data on twenty year old Hanna alkalinity reagent!

 

[Seansea]

How do you know your api nitrate was 2 based on the color?

Good at reading the colors

 

[Dan_P]

I've thought about this occasionally. When you ask large groups of R2R people about their alkalinity, you get these really cleanly normal distribution curves like this....

And this one's even better...

That's an amazingly smooth bell curve! Why?

My guess is that it means that in the context of hobby reefkeeping, the actual alkalinity doesn't really matter - within the broad agreement that 7 to 9.5 is the target. Also that so many people have a clear answer means that they have a number they like and they aim for it consistently. And their tank likes this consistent target more than experimentation.
I've never heard a reefer say "my tank really loves a swing up and down from 7 dKH to 10."

We could wonder to ourselves if everyone used a kit calibrated against lab standards, and charted their rate of coral growth by mass or length/month maybe the normal distribution wouldn't look like that - maybe it'd be skewed narrowly toward an actual "best" value.
But since that's not the hobby situation, my interpretation of this chart is that it's just a vote for consistency aiming at a widely agreed target giving good results.

(feel free to make up your own stories about these charts )

I like the story.

 

[Garf]

I bought another API phosphate kit to use in the Hanna yesterday. I noticed 3 things.

1) the zero phos calibration on new salt water was a lot higher than the previous test kit. Old test kit read 0.51 on Hanna, new test kit reads 1.10. (There May be a little phos in the salt I suppose), but that’s a big jump.

2) the slope of colour change seems to have changed dramatically. Previously there was a 1:1 relationship between API increase and theoretical increase. For example, simply subtracting the 0.51 starting point from any reading with API gave a good reading throughout the entire range. This appears now not to be the case with the new API kit. it’s actually a much shallower slope, almost 1:2. For example, a theoretical increase of 0.3 is resulting in an API/Hanna increase of 0.16.

3) initially I was getting extremely wobbly results, with numbers wobbling around by 0.14. Strangely this happened with the original test kit to begin with, but settled down after a while. I shook the living daylights out of both API bottles in the new kit (not in the instructions as far as I can see), and it settled down.

Waiting for Hanna reagents to arrive to get my sanity back.