My testing of Elos test kits

[Billybeau1]

Since the advent of the new Elos brand that is on the market, I decided to test this new brand against a number of other brand test kits I have on hand.

I tested my tank water which is currently at 1.0264, 8.04 pH and 79 deg

For calcium and magnesium, I used the double sample test to try and get a finer end result. The standard calcium test measures in 25 ppm increments but can be dropped to 12.5 per drop by doubling the water sample. The Mag kit measures in 100 ppm increments but can be dropped to 50 by doubling the water sample.

Of course this uses more reagent but I wanted to check the accuracy against other kits.

So here we go

CALCIUM

Elos 400 ppm
LaMotte 400 ppm
API 400 ppm
Salifert 415 ppm
Seachem 340 ppm (we've been down this road before)

ALKALINITY

Elos 10 dkh
LaMotte 7.8 dkh don't know whats up wit that
API 10 dkh
Old Salifert (with indicator) 10.6 dkh
New Salifert (without) 11 dkh
Seachem 9.8 dkh

MAGNESIUM

Elos 1350 ppm
Salifert 1350 ppm
Seachem 1060 ppm

I did purchase a PO4 kit from Elos and it supposedly can distinguish the difference between .01 and .05 ppm but my PO4 is so low right now, I cannot test the accuracy of this kit just yet. I'll have to shut my canister off and let the PO4 rise a little then test. I will test it against Salifert and API.

In summary, I found the Elos kits easy to use and provide reasonably accurate results.

About the only two negatives I could find is :

1) They give results to the whole number unless you use the double the water sample but this requires using twice as much reagent. This probably isn't a problem for most.

2) I'm an old guy and I can't read small print very well. I needed a magnifying glass to read the instructions.

Other than that, I think most of you will be happy with your ELOS kits. I might add, customer service seems to be A+ from what I've seen on our boards.

For your information, Marine Depot now carries Elos test kits.

As always, I state, please don't beat me up on these results. These were my tests on my tank and results may vary.

After all, you all know I am a testing fool.

[bdare]

Nice Job Billy!

[kfick]

Do you have a newer (one of those in the fancy repackaged Copper test box) or older Salifer Mag kit? Is it the 4 drops for reagent A?

I'm right with you there on the Seachem kits

Thanks for this great comparison post!

[Billybeau1]

Thank you guys.

I have two Salifert Mag kits. Yes one is in a relabeled Cu box and it uses 4 drops of reagent A. The other is in a normal box, but is a little older. They both match. The newer one has an improved dropper for reagent A.

Kinda reminds me of the Cone heads from the old Saturday Night Live.

[rbursek]

I have my Elos one the way from MD, was going to go with the Salifelt, but all are on BO then read some threads here on them, glad I went with Elos, also got a call from Bob S. on my 3 salt samples of RC, I was getting a Calc of 350 on a 1.026 mix, he came up with 390,390, and 399, still is sending 3 buckets out and I told him I use Seachem for my Calc test, he did not want to bash but he confirmed your test on it, they read low even when checked out with there test solution, apparently they do test kit checking too, makes sense, I have a problem with your salt based on my test, they run test with different hobbiest test kits to see where the discrepancy is, plus there lab kits. Thanks again, it keeps us from going crazy when we have this confirmation!!!!!!!!!
Bob

[Billybeau1]

Yeah, I use a lot of Seachem products and love them, but their test kits leave a little to be desired. I've voiced my concerns about the calcium kit for awhile now. Their total alk kit doesn't seem too bad.

I'm glad RC stepped up to the plate for ya. They are a good company.

[rbursek]

Thank you for getting the ball rolling.
Bob

[Billybeau1]

Originally posted by rbursek
Thank you for getting the ball rolling.
Bob

[mmotown]

It looks like API may be the way to go for my next Mg kit and CA. I am currently using Salifert. Good looking out on the testing!!!!!

[Mike O'Brien]

I like my Elos kits. They have the coolest looking boxes.

[Billybeau1]

Originally posted by Mike O'Brien
I like my Elos kits. They have the coolest looking boxes.

mm, Unfortunately, API does not make a mag kit.

[Fraggle Rock2]

So far I have only used the Mg kit. Seems good to me but I'd rather have a finer result without doubling the reagents - but I suppose that's not such a big deal.

My only real complaint is that I broke the glass tube on my second use of the kit! Those things are made of very thin glass and I broke it removing the plastic stopper.

Luckily I have a science geek type store near me and I picked up some nice glass vials for about fifty cents each. Much better than what came with the kit.

[Billybeau1]

If a more precise measurement is important then I still say the Salifert does a pretty nice job for the hobby grade kits.

But I was impressed with the accuracy of the Elos kit.

[Phantom Phish]

Interesting results.

Like a lot of folks, I've been struggling with test kits myself. Again like a lot of people, I was a long term believer in the Salifert kits. My faith in Salifert was shaken by all the posts regarding problems with their kits, and my own recent experience with getting unusual results with their newer alkalinity and calcium kits.

I decided to try and do my own semi-objecive analysis of several of the hobbyist test kits for calcium and alkalinity. I purchased new kits from Lamotte, Seachem, API and Salifert. I also obtained a mailing packet from AquariumWaterTesting. com. Unfortunately, I didn't run Elos kits, and in retrospect I wish I would have.

One morning, I collected samples from my tank, and mailed them to AWT. That same morning I ran each test kit three times, for both calcium and alkalinity, and recorded my data. And then I waited for the results to return form AWT.

AWT claims on their website to "use spectrophotometry, auto-titration and specialized ion specific probes to acheive an accuracy 100 to 1000 times greater than home testing procedures". My plan was to use the AWT results as my reference values, and compare my results from the above hobbyist kits with the AWT results to see which kit came closest.

My assumption of course, was that the AWT results were more accurate than the hobbyist kits, based on their assertions on the website. Obviously, that assumption could be challenged, because I don't really know that AWT is as accurate as they claim. But I don't know of any other "reference standard" that is available to the general public to compare my results with, so that's what I went with.

Anyway, in a nutshell, of the above kits, Seachem was much closer than the others to the AWT result for calcium, and LaMotte and Salifert were both the closest to AWT for alkalinity.

Just thought I'd throw that out there.

[Billybeau1]

Well, it's kinda funny.

I thought maybe I had a bad Seachem calcium kit but the reference solution that comes with it matches exactly. (425 mg/l) yet you see the difference it measures in my tank water. 4 other kits are close to each other and this one is low.

Thats the reason why I didn't pursue the issue. I just wrote it off.

That is one of the reasons I don't like reference solutions.

[Boomer]

See, I told you they were good kits

[Randy Holmes-Farley]

That is one of the reasons I don't like reference solutions.

Based on your experiences, which kits are in the most need of standard?

I'm thinking of what sorts of DIY solutions we might devise that are adequately accurate.

How accurate do we think that TDS meters are, without special calibration?

If they were good enough (say, +/- 5%), it would be easy to make an alkalinity standard with baking soda made to a specified TDS.

[lactose]

Quick Question if i may:

When you use the API Alk test do you fill to the line or put in 5 mL?

On most of the test tubes if I measure 5mL into the tube the top and bottom of the meniscus is above the line and in line with the API letters. I get results in line with my other test kits when I measure the 5mL versus just fill up to the line.

I am also pretty sure I am measuring 5mL "right" as it aligns to the 5mL line on the lamotte kit and other containers I have (I use the sample syringes from the salifert kits to measure)

[bdare]

Originally posted by Randy Holmes-Farley
That is one of the reasons I don't like reference solutions.

Based on your experiences, which kits are in the most need of standard?

I'm thinking of what sorts of DIY solutions we might devise that are adequately accurate.

How accurate do we think that TDS meters are, without special calibration?

If they were good enough (say, +/- 5%), it would be easy to make an alkalinity standard with baking soda made to a specified TDS.

Hey Randy,

I'm pretty sure you can buy TDS calibration fluid. I'm actually thinking about picking some up just for fun.

http://www.tdsmeter.com/products/cal...nsolution.html

Ben

[Randy Holmes-Farley]

Yes, you can, and that may be something worth considering in order to make some standards where you buy that and then DIY a variety of different standards.

The standards we could make from baking soda, Dowflake, or MAG flake would not be a perfect way to evaluate kits for seawater (since we've removed many potential interferences), but for at least some types of kits, if they cannot even get the standard right then one might worry about their ability to get seawater correct.

[Billybeau1]

Originally posted by lactose
Quick Question if i may:

When you use the API Alk test do you fill to the line or put in 5 mL?

On most of the test tubes if I measure 5mL into the tube the top and bottom of the meniscus is above the line and in line with the API letters. I get results in line with my other test kits when I measure the 5mL versus just fill up to the line.

I am also pretty sure I am measuring 5mL "right" as it aligns to the 5mL line on the lamotte kit and other containers I have (I use the sample syringes from the salifert kits to measure)

For the API kits, I find if you fill to the line, it is most accurate. If there is a slight concave, the lowest dip in the concave should be at the line. Lamottes syringe is different from Saliferts.

Have you ever noticed that the first time you draw water with a dry Salifert syringe, you have an air bubble at the top, but if you exhaust it and draw again, no bubble ?

This is because of the tip. 5 ml on the Salifert syringe take account for air in the tip, not water. Thats why you cannot consistently draw 5 ml from a Salifert syringe and try and put it in an API test tube.

Once you initially draw water and exhaust it, you do not exhaust the water in the tip. Hence, when you draw again, no air bubble. Over 5 ml.

Gee I hope that made sense.

[Billybeau1]

Originally posted by Randy Holmes-Farley
That is one of the reasons I don't like reference solutions.

Based on your experiences, which kits are in the most need of standard?

I'm thinking of what sorts of DIY solutions we might devise that are adequately accurate.

How accurate do we think that TDS meters are, without special calibration?

If they were good enough (say, +/- 5%), it would be easy to make an alkalinity standard with baking soda made to a specified TDS.

I don't believe we can make a standard that can be used for every brand salt mix. Like you said, many possibilities of interference and you know there is a big difference in many of these salt we use.

I wish it was just as easy to say, x amount of grams baking soda in ro/di will yield y alkalinity. But what happens when we test our tank water with x-brand salt mix.

I'm not a chemist, but, I think the other elements in the different salt mixes my play havoc with this theory.

I'm just not sure we could come up with and alkalinity standard that would be accurate across the board.

I think thats why some people report good results with some test kits and others not. I think the different brand salts are skewing the results of some test kits depending on what type chemicals they use in their reagents.

I realize calcium is calcium, and alkalinity is alkalinity, and magnesium is magnesium. But I wonder if other additives in certain salt mixes could be affecting the results of some of these test kits, giving false readings.

I'm just thinking out loud.

[Randy Holmes-Farley]

Total alkalinity should be much less prone to interference than other types of kits. Is that needed?

[anr211]

What would be a good way to test magnesium kits? I have a red sea kit showing my tank at 1550 and just got a seachem test (before I read this thread unfortunately) that shows it at 1180.

I'm really not convinced either test is correct.

[Billybeau1]

Originally posted by Randy Holmes-Farley
Total alkalinity should be much less prone to interference than other types of kits. Is that needed?

If a standard could be made to say +/- 5% accuracy, I think that would put lots of minds to rest. Assuming we wouldn't need beakers and scales to make the thing at home.