calcium test comparison - test reliability

jlinzmaier

jlinzmaier

Premium Member
Anyone have any thoughts on the reliability of different brands of Calcium tests????? (or any type of test kits for that matter)

Which brand is most accurate?

Which will give accurate results for a length of time after being opened?

I've previously used Seachem and Salifert test kits but I seem to get inaccurate results after the test kit has been open for a few months. I'm considering trying the cheaper brands like API or IO but I'm concerned about their accuracy.

What has everyone else had success with in the past??

For the longest time I thought Salifert was by far the best, but just recently I've had extremely inaccurate results from the alkalinity and calcium tests after maybe 10-15 uses over the last 2-3 months.

I assume all brands can become unreliable after being opened for an extended amount of time, however if I'm going to get new test kits each month or two, is it really worth spending the extra money on Salifert or other pricy kits? I don't know about you but I'd rather be spending that money on frags!!!! I don't want to waste money on pricey kits, but I wouldn't settle for kits that won't provide reliable results either.

Thoughts, comments, suggestions......
 
That thread is almost 2 years old. Things have changed since then.

I have not had any problems with my Salifert Ca++ test kit and is still the most reliable for me.

The API kit is a fine check and balance but will only get you within 20 ppm either way. I have found the API extremely accurate if you want to test it against your Salifert.

A Salifert test kit should last a year easy. But you must guard against contamination. I don't squirt unused titrant back into the bottle. Once I draw it out, it stays out. I also do not mix syringes with any other test kit. Also rinsing the test vial real good after each use is important.
 
I've ordered an API and IO kit and I'll test them both against the Salifert. I can already predict that I'm probably going to get varied results and I won't know any more than I did before.

The more I read about test kits the more I feel like it's all just a shot in the dark. How disappointing!!! We do our best to provide pristine water for our animals and we can't trust the tests we use to monitor our parameters.

Does anyone know of any reliable controls to test against???? From what I read it seems you can't even trust the quality of the control solutions that come with some of the tests.

I use IO salt. Does IO post any guaranteed analysis info? The info I have of IO salt analysis is second hand and I don't know how reliable it is.
 
I have used Hagen/Nutrafin for everything; pH, ammonia, nitrite, nitrate, alkalinity, calcium, and phosphate. I have an API copper test kit also. I think they are accurate, IMO. I have taken my water to That Fish Place, being that I only live 30 mins from it. They use salifert and gave me the same results as my Nutrafin kits. Just my 2 cents....

Brad
 
As I thought, the tests came today and this was virtually a waste of money. The IO and API end point color changes are so unclear that I don't know how anyone can get an accurate reading. Not to mention, (based on my best estimation of the end point color change) I got readings of 315 from API 400 from IO and 360 from my Salifert kit.

I was just on the IO website and they say that fresh IO water at a sg of 1.026 should read a ca level of 400. Tomorrow I'll mix up a fresh batch and test the kits against the new water as a control.

I bought some more alk kits and got quite varied readings with them also. API read 3.75 meq and the IO kit read 2.75meq. I'm going to trust the IO kit. The most recent info I have of freshly mixed IO salt at sg of 1.025 should read 4.0meq and that's about what the IO kit tested the last time I used freshly mixed water as a control. I've inquired with IO about guaranteed analysis info.

Overall, How discouraging!!!!!!

FYI, the API kits have a vial in them with a 5ml line. This line is not always accurate!!!! Instructions say to add 5ml of test water to the vial and the line on the vial is labled 5ml. I didn't even pay attention to the line and added 5ml from a syringe. The water level was about 1cm above the line????? I thought I made a mistake so I emptied it and did it again and the water came to the same level . The difference is about 0.5 ml which in my calculations could create significant differences in readings if you go by the line or add the accurate amount of test water. The other API kit I have has a vial which is about 0.3 ml innaccurate. (When water is placed in a vial there is a concave surface at the top - when I say I'm filling to the line, I'm getting the water level to the point where the bottom of the concave surface is to the line. The bottoms of these vials are convex to account for the displacement caused by the waters surface tension .)
If a manufacturer cannot even provide a vial labeled with the correct amount of test water to add, there is no way I'm going to test their test results so API is out for me.

How frustrating!!!!!!!!!!! Do any of these manufacturers perform quality controls?????? What does it take to get an accurate test??? At this point, I don't even care how much an accurate kit would cost, I just want to know what my damned calcium level is!!!
 
Does the IO go purple and then take a long time to turn to pure blue? I found that the SeaTest kit required a long wait after it turned purple, followed by 2-3 drops of titrant. The IO kit might have a similar issue.
 
Yes. Both the IO and API have a very quick and distinct change from pink to dark purple but the chage from purple to blue is very slow and unclear. Is the true value at the point of the drastic change from pink to purple or does it truly need to be blue. The change from purple to blue requires multiple drops and the change is so minimal that there is significant room for error based on color interpretation.
 
I'm looking into getting a Lamotte calcium test kit since that's the only other quality kit I've heard of.

Those of you that have used Lamotte kits - is the color change from pink to blue a clear change or is it or is it slow and unclear like the API and IO kits?? After trying the API and IO I can appreciate the clarity of the color change with the Salifert kits.

From what I have read of reviews, the Lamotte kits are boasted as "High End" and "top quality". Can anyone speak to that. Has anyone tested any Lamotte kits against control solutions.
 
The solution should go to a clear blue, not a hint of purple. I haven't used those kits, so I can't help much. The SeaTest kit had a problem with that color change, so I'm not surprised those tests have the same issue. I'd trust the Salifert, personally.

I have only used the LaMotte sulfide kit, and it seemed high-quality. Hard to judge, though.
 
My API kit shows a distinct change from purple to blue. As does my Salifert.

I have not tested the IO or the LaMottte.

For my eyes, purple and pure blue are pretty easy to distinguish.

And I'm an old fart. :lol:
 
<a href=showthread.php?s=&postid=11046886#post11046886 target=_blank>Originally posted</a> by Billybeau1
I don't squirt unused titrant back into the bottle. Once I draw it out, it stays out.
Click to expand...

Why would this be important if the unused liquid inside the syringe never makes contact with any other liquid?
 
Is the true value at the point of the drastic change from pink to purple
Click to expand...

Yes, that is the end point of the titration. At this point the indicator had begun to react with the reagent indicating the endpoint. The deep color is not needed and wrong.

I use this Ca++ test kit (API) btw and have found it to be just as accurate as others. Indeed you only get within 20ppm of the actual value, but that is fine for me I guess in my small volume. My coral can use up at least 10ppm per day, so why worry about a more accurate test kit, it would only give me different results depending on what time of day I tested.
 
I dump unused titrant back into the bottle, and haven't had any problems. I do keep the bottles capped as much as possible.
 
<a href=showthread.php?s=&postid=11096313#post11096313 target=_blank>Originally posted</a> by SuperNerd
Why would this be important if the unused liquid inside the syringe never makes contact with any other liquid?
Click to expand...

I didn't say it was important. I just said thats what I do. I'm sure putting unused titrant back in the bottle is fine as Bertoni stated. Maybe I'm just lazy. :D
 
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