NYOS Magnesium (MG) Reefer Aquarium Test Kit

Seems to work well.

NYOS test kit is one of the best products.I used Tetra, RedSea, Salifert. These products have both advantages and disadvantages.For example,RedSea has tough tools like syringe and glass bottle. But hard to read the index sign.Salifert has reliability. But hard to understand the instructions....IMO NYOS is located between RedSea and Slaifert.

My test kit says it will expire 5/2019. I have been testing for the passed 2 weeks and would get a reading of around 1100ppm. I began adding red sea magnesium and would test and it would show the magnesium rising proportionate to my dosing so I thought nothing of it other than being low in magnesium. Then magnesium kept dropping so I tested my reef crystals saltwater mix and nyos would read that a fresh batch of mix reading about 1150ppm. So figured I got a bad batch of salt. I purchased red sea pro salt which is rated at 1350ppm mg. Testing the red sea salt mix I again got a reading of ~1100ppm. The next logical step was to purchase a new mg test kit. Received salifert mg test kit today and my tank reads over 1600ppm! That is over a 400ppm difference. No doubt in my mind this test kit is inaccurate because I just about put half the bottle of red sea mg in my 25g tank.. I hate writing bad reviews but this could have caused serious damage to my pets. Stay away from this kit.

I had been curious to the NYOS brand of test kits since they first debuted. When my last Magnesium test kit ran out, I decided to give this a try.It seems to be of good quality, and so far the tests have all came back correct. I would recommend this test kit above many other brands.The only part I don't care for, is that 'stopper' in one of the syringes is tapered, rather than flat. And it makes it hard to judge exactly when you are at 1ml. Otherwise, I am happy with NYOS version of a Mg test kit!

I found out my corals were lacking magnesium. with this kit I can keep the levels where they need to be.

I have all of the basic saltwater test kits and I can get accurate readings. This single element test kit is pretty expensive and seems to repeatedly show I have little to no magnesium even a few hours after dosing. Its possible I'm at fault so I won't rate lower than three starts.

I have been using this test kit since Jan 2017 with no issues as long as the instructions are followed. Thanks.

Excellent test kit and easy to use