API Tests - How accurate do you think they are

[albertthiel]

Topic created today July 15

 

Reason: to get feedback on what users think/feel about the accuracy of the API test kit (Master kit or individual tests)

 

Please post your feelings on this thread ... Thanks

 

Albert

[MGDMIRAGE]

Any test kit is only as good as its batch. I've had good luck with API test kits they seem very accurate and affordable. I use a combination between API and Salifert. I've had mine tested against Elos and Salifert from the LFS and they have always been pretty much inline.

[Riotjock]

This is like asking your average electricity consumer, how well the nuclear power plant works. You'll get quite a few opinions, none of them very imformed.

[keydiver]

All test kits utilize the same basic principles. Phosphates and Nitrates are usually color comparison tests, and calc, mag, and alk are generally titrations using an indicator.

 

I have used API in the past and have found them to be very affordable and relatively accurate. However, IMO, red sea test kits are the most accurate and the most affordable. If you buy the packaged deals (ie reef foundation and algae control), you save. And you can buy refill kits instead of just buying another master test kit.

 

I think there are several reasons why API tests are less accurate than red sea. The first being the volume of water used. I think it's 5 ml of water, making a slight error during the titration skew the results by much more than it would if you were using 10 or 15 ml. I also like the fact that red sea includes a titrator, making it much easier to get accurate readings rather than just counting the number of drops.

 

This is like asking your average electricity consumer, how well the nuclear power plant works. You'll get quite a few opinions, none of them very imformed.

 

Nope... I don't see it

[Riotjock]

Let the uninformed opinions begin!

 

I THINK there are several reasons why API tests are less accurate than red sea. The first being the volume of water used. I THINK it's 5 ml of water, making a slight error during the titration skew the results by much more than it would if you were using 10 or 15 ml. I also like the fact that red sea includes a titrator, making it much easier to get accurate readings rather than just counting the number of drops.

 

For the record, the volume of water used for the test has nothing to do with how accurate the test is. For example, red sea uses 10 ml for the DKH test and 2ml for their CA test, and 5ml for their MG test. By the reasoning above, red sea's CA test (2 ml) would be less accurate than API's (5 ml).

[NanoTopia]

Water tested three times this morning, same sample.

 

Elos KH = 7.5 dKH (two separate bottles)

 

API KH = 10 dKH (one bottle)

 

Bad batch of API ? Maybe, but I trust the Elos. Can't risk thousands of $ on a test kit that is hit or miss. Elos is bang on bottle to bottle for me.

[thegambler26]

I agree that the red sea kits are far better. I do use the API test kits however and have had favorable results. I've never tested them against other kits but everything is doing well in my tank so they must be relatively accurate. The one thing that I do not like are there test vials. The loose fitting lids can leak on tests that need to be shaken,which is all of them. On tests like calcium or kh I've had that leakage affect the results.

[thegambler26]

Let the uninformed opinions begin!

 

 

 

For the record, the volume of water used for the test has nothing to do with how accurate the test is. For example, red sea uses 10 ml for the DKH test and 2ml for their CA test, and 5ml for their MG test. By the reasoning above, red sea's CA test (2 ml) would be less accurate than API's (5 ml).

You again! go away! I know you know more than everyone here about every subject, as I've gathered from all I've seen from you in the past! The guy gave his opinion and it seems reasonable. If you don't like it go somewhere else where maybe the people are up to your level of sophistication.

Sorry Albert to get off topic, but this guy drives me crazy!

[ward827]

I use the API tests for what they are: a simple gauge of how my water is doing at the time and letting me know if there's any problems. I haven't tested in a while because all my corals and fish are thriving. If something seems amiss in the tank, I'll test and try and make the necessary adjustments. W-

[Riotjock]

I agree that the red sea kits are far better. I do use the API test kits however and have had favorable results. I've never tested them against other kits but everything is doing well in my tank so they must be relatively accurate. The one thing that I do not like are there test vials. The loose fitting lids can leak on tests that need to be shaken,which is all of them. On tests like calcium or kh I've had that leakage affect the results.

 

Why don't you argue with my comment instead of resorting to silly personal attacks. Keydiver's comment is wrong, and as I pointed out, not based on real facts.

[NanoTopia]

Accuracy can be gained by changing the volume of sample. eg. Make a 5mL sample 10mL and half the amount of what a drop is equal to.

 

API KH for example, asks for a 5mL sample, use a 10mL sample. Each drop normally represents 1 dKH, now it will equal 0.5 dKH. You use more test product but get a more accurate result. This method of course will not work with all kinds of tests.

[Riotjock]

Accuracy can be gained by changing the volume of sample. eg. Make a 5mL sample 10mL and half the amount of what a drop is equal to.

 

API KH for example, asks for a 5mL sample, use a 10mL sample. Each drop normally represents 1 dKH, now it will equal 0.5 dKH. You use more test product but get a more accurate result. This method of course will not work with all kinds of tests.

 

The API test uses "drops" to calculate the DKH. Any inaccuracies are likely to be due to the drop size being slightly smaller or larger than a standard drop. By increasing the sample size, you are just using more reagant, but your test is still just as inaccurate, by the same percentage. You are just tricking yourself into thinking that it's more accurate. It's not.

[Iuvat]

Okay, I don't know if I'm color blind or if these colors don't really match the right shades of the comparison sheets...what would you guys say? Or is this a newb question? ( Oh and the tank just started cycling by the way, thats why the parameters are out of whack)

PH(API):

Ammonia(Elos):

[Riotjock]

Okay, I don't know if I'm color blind or if these colors don't really match the right shades of the comparison sheets...what would you guys say? Or is this a newb question? ( Oh and the tank just started cycling by the way, thats why the parameters are out of whack)

 

Hold the vials against the white part of the page, the way the pretty pictures on the back illustrate.

 

Did you use prime or other dechlorinator when you started your tank? Those screw up ammonia tests.

[Iuvat]

Yeah its the same color even on white. But no this is water I got from my LFS, from his main system, so I don't think so.

[Riotjock]

Yeah its the same color even on white. But no this is water I got from my LFS, from his main system, so I don't think so.

 

It's not the same color on white.

[NanoTopia]

The API test uses "drops" to calculate the DKH. Any inaccuracies are likely to be due to the drop size being slightly smaller or larger than a standard drop. By increasing the sample size, you are just using more reagant, but your test is still just as inaccurate, by the same percentage. You are just tricking yourself into thinking that it's more accurate. It's not.

 

By more accurate I meant in the case of the API test eg. end results could be determined by increments of 0.5 dKH instead of 1 dKH. For some people this accuracy is not necessary, for me it is.

 

 

The API test uses "drops" to calculate the DKH. Any inaccuracies are likely to be due to the drop size being slightly smaller or larger than a standard drop. By increasing the sample size, you are just using more reagant, but your test is still just as inaccurate, by the same percentage. You are just tricking yourself into thinking that it's more accurate. It's not.

 

What is a standard drop?

[Iuvat]

I say this because I tried it before, I'm not just guessing....You can have a picture if you'd like? Hmm. Well nevermind then buddy...thanks for the help?

[Riotjock]

By more accurate I meant in the case of the API test eg. end results could be determined by increments of 0.5 dKH instead of 1 dKH. For some people this accuracy is not necessary, for me it is.

 

The end results can not be determined in increments of .5 DKH, because the test isn't that accurate. If your tester makes "drops" that are 25% bigger than the drop is supposed to be, your tests are always going to be 25% off if you double, triple, or quadruple the sample size because you are always increasing the number of drops by an equal amount.

 

If your alkalinity needs to be measured in .5 intervals, I'd suggest you buy a test kit that measures in those intervals.

[NanoTopia]

The end results can not be determined in increments of .5 DKH, because the test isn't that accurate. If your tester makes "drops" that are 25% bigger than the drop is supposed to be, your tests are always going to be 25% off if you double, triple, or quadruple the sample size because you are always increasing the number of drops by an equal amount.

 

If your alkalinity needs to be measured in .5 intervals, I'd suggest you buy a test kit that measures in those intervals.

 

I see your point regarding drop size, the test kit I use (Elos) is NIST calibrated and the dispenser delivers the size of drop required for 0.5 dKH. We have to trust this is accurate, as hobbyists we generally do not have access to lab grade testing equipment.

 

Thank you for your recommendation, I do use a test kit that measures in 0.5 dKH increments. I have been referring to API since these are the test kit in question in the thread title.

[121a]

API for Ammonia, NO2, and NO3. Salifert for anything else. I like the API kits. I have no reason to not trust them. They have always confirmed what I was thinking the levels were going to be so that is enough for me. Then again, I hardly ever test

[albertthiel]

Let the uninformed opinions begin!

For the record, the volume of water used for the test has nothing to do with how accurate the test is. For example, red sea uses 10 ml for the DKH test and 2ml for their CA test, and 5ml for their MG test. By the reasoning above, red sea's CA test (2 ml) would be less accurate than API's (5 ml).

 

Not correct IMO ... when you take the recommended water volume and you are just slightly off what is needed then the lower the number of ml's will skew your results far more than if you are slightly off on a test that calls for 5 ml or 10 ml.

 

And IMO it is easy to be slightly off the amount of water that is needed for a test so I am more comfortable with the ones that require 5 or 10 ml.

 

If you can take absolutely accurate ml's of water your point may be valid but IME that is not what usually happens, also do you fill to the line with water having a hollow look or do you fill just above the line so the water level is absolutely right on the line ... remember that test tubes exist in two types : to hold and to deliver and both are not the same .. just do a search for the difference.

 

I am much more comfortable with a kit that requires a larger amount of water as if I am slightly off in the amount my result will not be affected as much as with tests that only require very small amounts.

 

Getting the right amount of water in the test vial can be a challenge in some cases unless one uses a syringe for instance to draw the exact amount out of the tank.

 

Albert

[NanoTopia]

Agreed 100% Albert.

 

I suggest one pick up a syringe that measures 5mL. This would be the most accurate way of delivering sample for the money. I have used a syringe to fill one of those supplied vials with the line indicating 5mL painted on it, those lines are not always painted in the right place.

[albertthiel]

Okay, I don't know if I'm color blind or if these colors don't really match the right shades of the comparison sheets...what would you guys say? Or is this a newb question? ( Oh and the tank just started cycling by the way, thats why the parameters are out of whack)

PH(API):

Ammonia(Elos):

 

Yes color comparisons can indeed sometimes be difficult to interpret that and I agree that this can be an issue with many of the brands.

 

I used Tetra for some time and found it hard to find an exact match when testing, i find also that with the API where they recommend wait for 5 minutes ... that if you wait for longer the color will change even more and you may get the impression that your nitrite level for instance is actually higher than it really is.

 

Another problem with most tests that I have also run into is that they expire rather quickly, some as soon as 6 months after they have been manufactured and you never know how long they have been at the wholesaler and at the LFS, so you can sometimes end up with a set of tests that will be inaccurate because the chemicals are no longer potent enough to give correct results.

 

This appears to be a problem with most kits, the problem with some if not most is that no expiration dates are given, so how are we to know whether they are still good, and that is why IMO it is good to have two different types, or to test at home and then have an LFS do the test again and compare what you got and what they got. That should give you a pretty good idea of whether your tests are still good as LFS use them a lot more than a typical hobbyist does IMO.

 

FWIW

Albert

 

 

Agreed 100% Albert.

 

I suggest one pick up a syringe that measures 5mL. This would be the most accurate way of delivering sample for the money. I have used a syringe to fill one of those supplied vials with the line indicating 5mL painted on it, those lines are not always painted in the right place.

 

+1 you are absolutely correct .... (unfortunately for all of us).

 

Using a syringe that is marked for # of ml and transferring that water to the vial would IMO ensure that we have the correct ml of water needed.

 

The doubling of the amount of water mentioned in another post does work for some tests indeed but not for all.

 

Albert

 

 

API for Ammonia, NO2, and NO3. Salifert for anything else. I like the API kits. I have no reason to not trust them. They have always confirmed what I was thinking the levels were going to be so that is enough for me. Then again, I hardly ever test

 

Are you having an LFS test your water then ?

[Zer0]

Look, I'm not trying to be some website edicate nazi, but Albert, this isn't the correct forum for this discussion. This thread belongs in the Water Chemistry section, not the Members Aquariums section. The only reason I mention this is because these seperate sections were created for a reason; so people looking for information know exactly where to find it. Why would anyone look for information on these test kits in a section dedicated to showing off member aquariums, right?

 

/rant