Great Aquariums Start Here
Live Chat Support
    Free Shipping
  • FREE Shipping ON $75+
  • 14-Day Low Price Guarantee
  • Low Price Guarantee
  • Same Day Shipping
  • Same Day Shipping
99% of items we carry qualify for FREE SHIPPING in the contiguous United States if you spend $75 or more. Learn More
If you find a product we sell for a lower price at another online store, we will match their price to ensure you always pay the lowest amount when you shop with us. Learn More
Same Day Shipping
We promise to ship your order as fast as humanly possible. In fact, 99% of orders placed before 2 pm EST ship the same day! Learn More
Home » Saltwater Aquarium Supplies  » Test Kits  » Specialty  »  Elos Aqua Test Kit - General Hardness
Elos Aqua Test Kit - General Hardness

Elos Aqua Test Kit - General Hardness

Average Rating 3 4
Write A Review
Product Review
We value your opinion & experience
Thank you for taking the time to review our products!

This is a Product Review for: Elos Aqua Test Kit - General Hardness
Name to display on the review:
Location (ex: Anaheim, CA):
Your experience level:
How would you rate this product?
Review Title:
Write your review:
(Please focus on product quality and performance)
This item has been discontinued
Item #:
Notify Me
Just enter your email address below and we'll let you know when the product you are looking for becomes available!

Item Code:
Your Email:
Add to Cart or Notify Me
This item is temporarily unavailable but will be back in stock soon.

Item #
Click the Add To Cart button below if you'd like to reserve this item today. Any other items included in your order will be immediately processed and shipped. We will ship this item separately as soon as it arrives. We will not charge you for this item until it ships and you will incur no additional shipping charges.
Enter your email address in the field below and click the Notify Me button if you'd like us to send you an email when this item becomes available. Although you will be immediately notified when we have stock on hand, we will not reserve any units for you; you must return to our website and place an order.

Add to Wishlist
Select Wish List:
Comments (up to 200 characters):
Quantity Desired:
Quantity Received:
Marine Depot 60-day Returns
At Marine Depot, we stand behind our products. That is why we offer a 60-day return period: one of the best in the industry! Learn More

Elos Aqua Test Kit - General Hardness Information

Product Manuals & Documentation


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.

  • 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.

    Elos Aqua Test Kit - General Hardness Reviews

    Average Rating
    (4 reviews)
    Sort Reviews By:

    Tube broke, Hard to decipher!!

    Reviewers Rating Unsatisfactory

    Posted: 2/21/2014 from MOODY, AL UNITED STATES
    1.0 5
    Experience Level: Expert

    Comments: 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.

    Did you find this review helpful? Yes No

    Elos Aqua Test Kit

    Reviewers Rating Great

    Posted: 6/28/2010 from Leo, IN UNITED STATES
    4.0 5
    Experience Level: Intermediate

    Comments: 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.

    Did you find this review helpful? Yes No


    Reviewers Rating Below Average

    Posted: 8/15/2008 from MADISON, WI UNITED STATES
    2.0 5
    Experience Level: Beginner

    Comments: 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.

    Did you find this review helpful? Yes No


    Reviewers Rating Excellent!

    Posted: 1/23/2008 from LAS VEGAS, NV UNITED STATES
    5.0 5
    Experience Level: Intermediate

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

    12 of 12 People found this review helpful, did you? Yes No

    WIN A MEDIA REACTOR! Sign up for hot deals, helpful videos, and a chance to win an Accel Aquatics FR-30 Media Reactor!