Comments: My wife does the testing (I take care of almost everything else) so I can only relate to what she has told me. We tried a few other test kits and the ELOS seemed to be inline with test results from other kits. My wife likes the ELOS test kits because in her opinion they are easier to use and we seem to get fairly accurate results (compared with other test kits). We have never sent in samples to a lab but my tank is thriving so I'll go by that until I have the feeling to think otherwise.

Comments: I have always trusted Elos test kits and get good results with the CA and ALK kits. NOT THE SAME with the Mg kit.
<br />1st test: reading 1600. Seemed high since I had not dosed for 2 months. Test 3 more times, same result.
<br />2nd test: mixed new SW using Instant Ocean, 1700 was the result. Anyone familiar with this salt knows 1700 is impossible.
<br />3rd test: took my tank water sample to LFS and they found my water to have a reading of 1150. Had them test the new mixed water, 1300.
<br />4th test: had the LFS use my Elos kit and followed same directions, same outrageously high result.
<br />Contacted Elos and got the run around. After all the testing the regents are almost empty.
<br />Went back to Salifert, very reliable for Mg testing. I still use Elos for CA and ALK but with caution.

Comments: Good product, bad instructions. They do not tell you at least in the english verision that you have to dump the solution from pahse one of test bottle, and refill with aquarium water for phase two. I would have used all of part D, if I had not taken the time to research the intreuctions on line.

Comments: Salifert is easier and quicker. Tried this one out only because rep told me it sells more. It gives you readings in a scale of 50 (i.e. 1300, 1350, 1400, 1450......). Still a good test but prefer Salifert due to "tighter" readings and quicker results.

Comments: This test kit is very easy to use, if you have already used alkalinity/calcium test kits you should have no trouble using this one. You will need to take 2 samples from your fish tank and count the number of drops it takes for the water to change its color using different chemicals with each sample. Then make a quick math to calculate the concentration of magnesium. The precision if of 50 ppm, which is good. The only down side is the test tube that comes with the product. Mine broke on the first time I tried to use it. This is not an issue since I have several test tubes from other kits. That is the only reason I don't give it a 5-star rating.

Comments: The test vial is very fragile and likely to break upon inserting or removing the stopper driving shards of glass into your hand. DO NOT BUY!!!

Comments: Once you get the hang of how to use this test kit, it's actually very easy. I read a couple of the reviewers comments before ordering it, and learned that the key here is that this is a TWO PART TEST. Be sure to dump out the first color change from red/orange to green; then count drops again for the color change from pink to blue. Color change is very dramatic and easy to see, and the test is accurate to increments of 50.

Comments: A agree with the person that put one star about the directions. I did the test 3 times before I figured out I wasn't dumping out the first phase test. So I wasted a lot of drops.
<br />To save anyone some frustration after the water turns green from test bottle A... dump out the water before going to the next test phase.
<br />
<br />So the directions could be more clear but I ended up liking the test vs. other popular brand.
<br />One reason is it can measure well above 1500. And I have added too much Mg more than once.
<br />
<br />The last brand I was using maxes out around 1500 cuz the syringe simply won't hold more.
<br />
<br />As far as 100 increments that's what I was expecting from reading about it but my directions lead me in 50 increments.
<br />
<br />On the second phase .. .if you have drops after the math.. it would be 1200... 26 drops would be 1250.

Comments: Good test but... Instructions are poorly written. After counting the drops for reagent A dump out the test and get fresh water to finish the test. I had to call Elos and the guy (great customer service BTW) who answered the phone said that a lot of people are having similar problems. Other than the instructions the test seems to be accurate and I will order again.

Comments: i was almost convinced that this would have been a great test kit after using the PH and KH test kit. This one was kind of bad from when it starts telling you to use the steps from the beggining again but for some reason you might miss that "except use the chemical D dropper this time". i had to do it twice and ran out of the D fluid since it's only a small container. it should have been as big as the "A" fluid. First i made the mistake of using the "A" 2x because of bad print then the other problem i when they said the color is suppose to turn light blue! it never turned light blue but it turned lighter green than the dark green when it first started. i kept adding "D" drops until i figured something is wrong when i added about 150 drops and it wasn't turning light blue and the calculation came out 4000+. When i decided to try again but i figured this time as soon as i see lighter green that was going to be it...then the bottle emptied out! i don't think i'll get this one again and find something that's much precise when it comes to color matching and specific explanations.

Comments: After trying many of the "quality" kits out there, I settled on this as testable to 50 ppm, consistent from batch to batch, and being color blind for certain colors, it is very easy for me to see color changes for the two part test (Orange to Green and Pink to Blue). It is very easy to use.
<br />
<br />The reviews saying only 100 ppm accuracy is incorrect and trying to sell you the test kit they mentioned which I tried and did not like as not consistent and hard for me to see color changes.

Comments: Elos have the easiest to use Magnesium test kits on the market.

Comments: Nice test kit. Mine did not come with instructions. Guys at Marine Depot are sending a copy. That's why I shop at Marine Depot.

Comments: Super easy test to perform. Fast color change at the transition point, much better than a color chart. The test is similar to a KH test in that you count the number of drops of the final reagent.

Comments: This test is not precise enough! If you have a reef tank with a lot of live, this test will give you only "more-less" readings. Thats because one drop=100ppm. So, you have a results such as 1300ppm, 1400ppm, 1500ppm and thats not close enough for figuring out a dosing of magnesium.Dont waste your money and rather get a Salifert. Price is the same and you will get readings as a 1200, 1230, 1260, 1290, 1320, 1350 etc. I did give this products two stars just because it is easy to use. Hope I did help.

Comments: Takes awhile to get used to after using another brand but much easier and faster! Great test kit

Comments: This kit is pretty easy to use, and makes you feel like a chemist while using it!!! I don't have anything to compare it to, but apparently it's pretty accurate too.

Comments: I have used a Salifert for 2 yrs. The Elos tested the water 4oo pts higher and a Red Sea Tested out 250 pts higher. I would not recommend this kit. Also this kit goes in 100 pt increments mest others go by 20 pts.

Comments: Pro: very simple to use, no need to measure to the 10th of a ml. only 3 steps. fast. easy to read color changes.
<br />
<br />con: only 100ppm increments.

Comments: I found this kit reasonably accurate and easy to use. Good color end point. Only drawback is it reads in 100 ppm increments. Can be improved to 50 ppm by doubling the water sample but it will use more reagent.

Comments: The Elos Aqua Mg test kit is great...very simple, with only 3 steps, and easy to interpret results. The color change is obvious, unlike many other tests on the market. I'm looking forward to trying other tests they have!

Comments: Ran out of my Salifert Mg kit, and everybody was having issues at the time with Salifert customer service. Heard great reviews about Elos test kits, & they are no joke. In my opinion, this kit is the best out there, & very easy to use.

Comments: I've read from other people and now I'm telling you. Most present day reef salt mixes do not contain the desired level of Mg. This kit is essential to establishing the base magnesium level of your salt mix, so you can correct it to the desired level from there. 1300ppm seems to be general consensus. Be very patient. Know that it take considerably longer to raise Mg than dKH or Ca.