Elos Aqua Test Kit - General Hardness

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This item has been discontinued.

Elos USA


General Hardness is primarily the concentration of Calcium (Ca++) and Magnesium (Mg++), the two most important metal cations with more than single positive charge. If the amount of these salts is low, then the water is called soft. When their amount is higher, the water is called hard.
Total hardness is normally given in German degrees (dH°), whereby 1 dH° is equal to 10 mg/Lt dissolved Calcium oxide. The concentration of these salts inside the water effect the biological functions of plants and fishes. The optimal value for the General Hardness depends on the species of fish and plants. Where many African and South East Asian species flourish in relatively hard water, South American ones may need soft water. By the way, if a range of hardness of 3 to 16 dH° is accepted, a range of 4 to 10 dH° is considered to be ideal.

The periodical analytical evaluation of GH in an aquarium is crucial for a serious aquarium enthusiast.
ELOS AquaTest GH, as well as all the other titrimetric test kits of this line, grant very high precision thanks to several procedures like the use of calibrated droppers with constant and predefined drops of 0,03 ml each, the validation of our reagents, through NIST (National Institute of Standard and Technology) validation and the careful stock management to supply to our customers ONLY the freshest production batch.


  • High precision: thanks to the use of calibrated droppers
  • NIST validation: each batch is validated using NIST (National Institute of Standard and Technology) samples.
  • High number of test per kit: up to 50 test (with a standard GH level of 10 dGH)
  • "Safe reagents": reagents and testing procedures are based on Low Risk Reagents. None of our test kits are based on Toxic Reagents.

  • Product Manuals & Documentation

    Elos Aqua Test Kit - General Hardness

    Owner's Manual available for download in Adobe PDF file format

    Manufacturer Info

    ELOS: the ultimate supplements and equipments for marine and planted aquariums.

    Elos is an aquaristik company that is exclusively dedicated towards the development, production, and marketing of specialised, high quality products for the aquarium market.

    We apply the latest advances in marine and fresh water sciences into our manufacturing and products. We are environmentally responsible as well as respectful of the key ethic rules on employment and production. Almost all our products are made in Italy, through few, well trained Internal Employee with the help of key external suppliers, Universities and Research Centres.

    Our commitment is to invest in the future, we take great care of details and innovations but beside this we also take care of our traditions. We apply modern process, but we also use traditional techniques, employing local craftsmen for the production.

    We take great care in designing our products, and packs to simplify their use making them pleasant to see and to touch. From the first contact with our products you will immediately perceive the care to produce them and the great attention toward each single detail.

    For all this we invite you, by heart, to try our products. Join your passion with us, use our products and make the best out of them and, we are sure, You will experience the delight of creating your personal, unique underwater world in a beauty you have never seen before.



    Experience Level: Expert

    Tube broke, Hard to decipher!!

    The test tube broke as I was putting the cap on for the first time. Like most GH test kits, you add one drop, shake it, add another, shake it and so on until the colors change. This test kit in particular is from Red to Green and they are VERY hard to decipher!!! The API kit is much easier to see the color change. I will continue to test tap water and remineralized RO water to see if the accuracy of this kit is better than API. But so far, I think I just wasted $17!! Luckily I have old API test tube lying around.

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    Experience Level: Intermediate

    Elos Aqua Test Kit

    I like the simplicity of the unit; however, I would prefer a similar type of unit that could read in the 2.5-10 grains per gallon or 40-170 PPM range.

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    Experience Level: Beginner


    This is a confusing test kit. It comes with a syringe to fill the test tube, but the going to the 5ml fill line actually gives you more than 5ml. The test tube has no markings at all. Should I do 5ml as the instructions say, or use the 5ml line on the syringe as the instructions also say? I end up using a tube from another test kit and do a real 5ml. I hope that's right.

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    Experience Level: Intermediate


    Very good test kit. Easy to use, & accurate. Compared to Salifert, IMO this is a better test kit.

    12 out of 12 found this review helpful

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