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Old 05/19/2017, 05:58 AM   #1
Spectorman
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Why bother testing?

I have a salifert test kit reading 10dkH. My API kit says 3dkH. What the heck is that? The salifert calcium kit says 500ppm and the API Calcium says 400. What's up with that?
My tank has always flourished. Lately,not so much. Admittedly,it is 60%my fault. I stated before in a post that my husbandry has been mildly less than satisfactory. Since,I am dying to get back on track. I have been testing to figure out what's up. That is what led to this post.
What should I believe. I am typically not a numbers chaser.


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Old 05/19/2017, 06:00 AM   #2
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Why bother testing?

Test a few more times. Especially the alkalinity test I'm willing to bet user error. Or your test kit expired/is bad.


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Old 05/19/2017, 07:01 AM   #3
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No reason to even own an api alkalinity test honest. It measures at a resolution of 1.0 dkh. That alone is reason to toss it in the garbage. And agree to the above. Most funky test results are from user error or expired reagents


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Old 05/19/2017, 08:01 AM   #4
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I'll check the exp.dates. I bought them in December.


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Old 05/19/2017, 08:24 AM   #5
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If you have the energy to "figure out" the testing conflict, run the alkalinity titration for each kit with a pH in the test solution. The pH should be about 4.3 at the neutralization point, where the color has just completely changed. This approach will eliminate any error caused by confusing color changes. If the pH is not calibrated, you can still use the pH readings. Regardless of the actual pH, determine whether the endpoint occured at roughly same pH (it will if both kits are working, or broken in exactly the same way which is unlikely).

If the titration results still vary widely, you can conclude the the titrant strength is off. Determining which titrant is the corect strength would require having access to a standard with a known alkalinity.

The calcium titration differences are close enough to suggest that improving technique will get them closer.


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Old 05/19/2017, 10:02 AM   #6
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Are you cleaning the test tubes well after use?
If you repeat the test 3 times with the same kit, do you always get the same result?
How careful are you about the water level in the test tube before you start?

I'm just asking basics. But they do matter.

I use API kits all the time for Ca and alk. Once in a great while I get a flier. So I test again and 90% of the time I get the same flier of a reading and 10% I get a different number, more like what I was expecting. Those errors are on me. I did something wrong.

If I get the same wild number 2 tests in a row with the API, I test again with a Salifert test kit. 99 times out of 100 I'll get a number that is VERY close to what I got with the API kit.

When I saw people were slamming API kits (like Bpb) I bought some Salifert kits. That was about 9 years ago. Then I started testing with both and sure, the results vary a little bit, but always less than 5%. The API would say alk was 8dKh and the Salifert would say 8.4dKh... big deal. Or Ca would be 440 and 450, again, big deal.

If your numbers are that far off, I'd get a friend over with their test kits and try again. You may have a bad kit, it happens. Or it could be you're not being careful enough to do the test exactly the same way each time.


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Old 05/19/2017, 11:03 AM   #7
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I wouldn't even necessarily say I am slamming the api kits. Mine have always tested close to the same range as more expensive higher resolution kits. But a 1.0 dkh swing is pretty large and if you're testing alk regularly to try and dial in stability it just makes sense to have a higher resolution test


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Old 05/19/2017, 11:45 AM   #8
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Can't you improve the accuracy of the API by doubling the amount of test water? I thought I read that somewhere.


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Old 05/19/2017, 11:57 AM   #9
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Quote:
Originally Posted by Ron Reefman View Post
Are you cleaning the test tubes well after use?
If you repeat the test 3 times with the same kit, do you always get the same result?
How careful are you about the water level in the test tube before you start?

I'm just asking basics. But they do matter.

I use API kits all the time for Ca and alk. Once in a great while I get a flier. So I test again and 90% of the time I get the same flier of a reading and 10% I get a different number, more like what I was expecting. Those errors are on me. I did something wrong.

If I get the same wild number 2 tests in a row with the API, I test again with a Salifert test kit. 99 times out of 100 I'll get a number that is VERY close to what I got with the API kit.

When I saw people were slamming API kits (like Bpb) I bought some Salifert kits. That was about 9 years ago. Then I started testing with both and sure, the results vary a little bit, but always less than 5%. The API would say alk was 8dKh and the Salifert would say 8.4dKh... big deal. Or Ca would be 440 and 450, again, big deal.

If your numbers are that far off, I'd get a friend over with their test kits and try again. You may have a bad kit, it happens. Or it could be you're not being careful enough to do the test exactly the same way each time.

They absolutely,matter. Yes. I always clean with tap the before I test I dip the cylinders and caps in tank water,shake them out then fill appropriately.


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Old 05/19/2017, 09:57 PM   #10
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No reason to even own an api alkalinity test honest. It measures at a resolution of 1.0 dkh. That alone is reason to toss it in the garbage. And agree to the above. Most funky test results are from user error or expired reagents


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I disagree about the API kit. Seems perfectly fine to me.

Big 3 Shootout Alk, Ca, Mg: RedSea, Nyos, Elos, Salifert, API, Hanna ... ...
http://www.reefcentral.com/forums/sh....php?t=2558208


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Old 05/20/2017, 08:27 AM   #11
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I disagree about the API kit. Seems perfectly fine to me.

Big 3 Shootout Alk, Ca, Mg: RedSea, Nyos, Elos, Salifert, API, Hanna ... ...
http://www.reefcentral.com/forums/sh....php?t=2558208


Again...missing the point entirely. I'm not reading a mega thread as I'm not in the market for new tests and I've already used just about all of those in that thread anyway and have decided on what I prefer...but unless the thread has a way to increase the resolution of the API test kit, it's accuracy and consistency don't matter if it only measures in 1 dkh increments. It's no faster to use than a Hanna checker so it isn't saving any time either.

Again folks. Even if it's accurate, it is too low of resolution. That is my only gripe. But it's a big one. Enough of one to not own them. It's my same complaint with their nitrate and phosphate test kits as well. If you don't give AF about resolution and are fine testing in large ranges and don't care about precision stability, then they're great, easily accessible, and inexpensive.


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Old 05/20/2017, 09:20 AM   #12
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Again...missing the point entirely. I'm not reading a mega thread as I'm not in the market for new tests and I've already used just about all of those in that thread anyway and have decided on what I prefer...but unless the thread has a way to increase the resolution of the API test kit, it's accuracy and consistency don't matter if it only measures in 1 dkh increments. It's no faster to use than a Hanna checker so it isn't saving any time either.

Again folks. Even if it's accurate, it is too low of resolution. That is my only gripe. But it's a big one. Enough of one to not own them. It's my same complaint with their nitrate and phosphate test kits as well. If you don't give AF about resolution and are fine testing in large ranges and don't care about precision stability, then they're great, easily accessible, and inexpensive.


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Not to low for everyone. That is your perspective.

If you don't care to read my arguement that it is satisfactory for many, including myself, then we're done as a discussion includes two or more people (usually.)


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Old 05/20/2017, 09:26 AM   #13
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I can see you're offended. So to humor you I read the alkalinity post of salifert vs api. It is exactly as I said. Close enough. Accuracy not the problem. Just too low of resolution. If you like to keep a tank full of leather corals or Zoas, or just happen to have a blue thumb and can keep sps thriving with no effort and minimal testing. Kudos to you, the other 95% of us appreciate a higher resolution test.


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Old 05/20/2017, 09:42 AM   #14
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I can see you're offended. So to humor you I read the alkalinity post of salifert vs api. It is exactly as I said. Close enough. Accuracy not the problem. Just too low of resolution. If you like to keep a tank full of leather corals or Zoas, or just happen to have a blue thumb and can keep sps thriving with no effort and minimal testing. Kudos to you, the other 95% of us appreciate a higher resolution test.


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You seem to have a narrow focus on the hobby and this discussion and really didn't read my thread then. I gave an arguement for both sides as well. Just because something doesn't meet your requirements doesn't make it junk.


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Old 05/20/2017, 09:51 AM   #15
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I can see you're offended. So to humor ...
Fwiw, not offended at all. I like clarity and a good debate. No humor required but always welcome.


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Old 05/20/2017, 10:48 AM   #16
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I would disagree on narrow focus. Just prefer something better than the API alkalinity and nitrate testers specifically. I use them on my freshwater tanks though and am fine with that. Everyone is welcome to use whatever they like. But if the op is presenting an argument for or against testing, and states that he uses an API alk test, naturally I'll recommend something better. Otherwise what's the point of the post if not to ask for some recommendations


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Old 05/20/2017, 11:49 AM   #17
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Again...missing the point entirely. I'm not reading a mega thread as I'm not in the market for new tests and I've already used just about all of those in that thread anyway and have decided on what I prefer...but unless the thread has a way to increase the resolution of the API test kit, it's accuracy and consistency don't matter if it only measures in 1 dkh increments. It's no faster to use than a Hanna checker so it isn't saving any time either.

Again folks. Even if it's accurate, it is too low of resolution. That is my only gripe. But it's a big one. Enough of one to not own them. It's my same complaint with their nitrate and phosphate test kits as well. If you don't give AF about resolution and are fine testing in large ranges and don't care about precision stability, then they're great, easily accessible, and inexpensive.


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Resolution of any drop counting test can be increased several ways.

1) Increase the volume of the test sample. Very simple but this increases the cost per test.

2) Rather than count drops, measure titrant volume with a 1 mL syringe. You need to measure the volume of one drop, or better, measure the volume of ten or twenty drops. Further resolution is achieved by using a 1 mL syringe with a 22 or 24 plastic tip and adding "half drops", i.e., squeezing out a tiny drop and touching it to the side of the test vessel to dispense it, just above the test liquid level and swirl in. I use this approach to test 1 mLsamples.

3) Dilute the titrant. This will require accurately increasing the titrant volume with distilled water. You could draw up 0.5 mL titrant in a 1 mL syringe and then without emptying it, draw up 0.5 mL distilled water. Empty the syringe into a clean vial and swirl to mix. Twice as much titrant is now required, so, one drop becomes equivalent to a half drop of the original titrant.


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Old 05/20/2017, 11:57 AM   #18
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I would disagree on narrow focus. Just prefer something better than the API alkalinity and nitrate testers specifically. I use them on my freshwater tanks though and am fine with that. Everyone is welcome to use whatever they like. But if the op is presenting an argument for or against testing, and states that he uses an API alk test, naturally I'll recommend something better. Otherwise what's the point of the post if not to ask for some recommendations


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Well, you believe the majority of people that have an aquarium are SPS keepers and care about high resolution on an alk kit. You threw out the arbitrary percentage. That tells me you have a narrow focus on the hobby.

You also mentioned the API kit can be thrown away as garbage. I countered it is not and serves its purpose just fine.

To add, just because a kit offers high resolution doesn't make it more accurate. There are certain parameters where high resolution can be benificial. Some like Alk high resolution could be benificial to some and others not at all. The recommended range for alk is rather wide from 7dkh to 11dkh.

Keeping alk stable is good. Having high resolution may be interesting but having a high resolution kit is not necessary. A small swing in alkalinity happens all the time anyway. If you want ultimate control then some thing like the kH Gaurdian is out and others like it are to follow.

Otherwise I rarely test my alkalinity levels. I watch my pH and if it swings more or less then normal then I might check my alkalinity as it may be low or high and not buffering the pH like it was.

Many ways to do this. But I have yet to see anything convincing that shows the API kit is junk.


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Old 05/20/2017, 12:22 PM   #19
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Fair enough. Naturally we will all defend the products we settle on no matter what. The OP can make his or her own choice at this point to continue testing or stop. Or continue using something they're unhappy with or try something different.


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Old 05/20/2017, 12:35 PM   #20
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I also use Salifert and have used it for all the saltmix testing.


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Old 05/21/2017, 05:10 AM   #21
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Jason, I agree with you and all you have said here. But this comment is the one that hits home the most with me.

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To add, just because a kit offers high resolution doesn't make it more accurate. There are certain parameters where high resolution can be beneficial. Some like Alk high resolution could be beneficial to some and others not at all. The recommended range for alk is rather wide from 7dkh to 11dkh.
I think way too many people see higher resolution as the same thing as being more accurate.

It's kind of like the use of a refractometer over a hydrometer. I 'calibrated' 2 hydrometers to a calibrated refractometer some 5 or 6 years ago. Both hydrometers were not accurate. So I marked each with the error rate, one read 0.005 to low and the other was 0.003 to low. For several years I used the hydrometers and every 3 or 4 months I'd double check them with a freshly calibrated refractometer. Occasionally the refractometer needed a slight adjustment to be accurate, but the hydrometers always have the exact same error rate as they did the very first time I tested them. Yet many people say hydrometers are junk. If it has finer resolution and/or costs more, it must be better...


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Old 05/21/2017, 06:46 AM   #22
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Jason, I agree with you and all you have said here. But this comment is the one that hits home the most with me.



I think way too many people see higher resolution as the same thing as being more accurate.

It's kind of like the use of a refractometer over a hydrometer. I 'calibrated' 2 hydrometers to a calibrated refractometer some 5 or 6 years ago. Both hydrometers were not accurate. So I marked each with the error rate, one read 0.005 to low and the other was 0.003 to low. For several years I used the hydrometers and every 3 or 4 months I'd double check them with a freshly calibrated refractometer. Occasionally the refractometer needed a slight adjustment to be accurate, but the hydrometers always have the exact same error rate as they did the very first time I tested them. Yet many people say hydrometers are junk. If it has finer resolution and/or costs more, it must be better...


Technically though, wouldn't those hydrometers then be considered inaccurate, but consistent?


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Old 05/21/2017, 08:19 AM   #23
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Ron I totally agree. Plus, the fact if someone really wants higher resolution with the API kit or Elos that has the same resolution all they would have to do is double the sample volume. Then they would count each drop as .5dkh. Accuracy hasn't changed at all.


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Technically though, wouldn't those hydrometers then be considered inaccurate, but consistent?
Not any less accurate then a Milwaukee digital refractometer. Once the hydrometer is marked it is essentially calibrated.

But a hydrometer has a lot of restrictions to make sure it is used right for it to maintain that accuracy. Otherwise it's a perfectly fine way to determin the specific gravity of seawater for us in the hobby.


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Old 05/21/2017, 08:44 AM   #24
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And to add I haven't used a hydrometer in years. I use several instruments to determin salinity. An analog refractometer, 2 digital refractometers, and 2 different makes of conductivity meters. So, I have no stake in defending a hydrometer.

Most ALL test kits or equipment are perfectly fine for our hobby. There are a few I found lacking. Chasing numbers can be fun for some but could easily lead to disaster for others.

Seawater is very complex and so much that over many centuries how seater is defined and tested has changed numerous times and probably will again in the future. Even something like ICP-OES is terrible at testing the trace and even minor elements in seawater. Its just ok for the major elements. And is easily influenced by the methods used to prepare, perform, and analyze the testing.


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