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Aquarium Supplies
Home » Saltwater Aquarium Supplies  » Test Kits  » Carbonate Hardness  »  Elos Aqua Test Kit - Carbonate Hardness
Elos Aqua Test Kit - Carbonate Hardness

Elos Aqua Test Kit - Carbonate Hardness

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Elos Aqua Test Kit - Carbonate Hardness Information

Product Manuals & Documentation


The alkalinity of a solution refers to its capacity to buffer against drops in pH. It is a measure of the concentration of various negatively charged ionic compounds (anions) such as carbonates, bicarbonates, borates and hydroxides in the aquarium water. The concentration of these ions determines the buffering capacity of the water to maintain proper pH. If the percentage of the hydrogen carbonate and carbonate ions is too low, the pH value of the water may drop severely (acidity drop) causing a life threatening condition for many plants, invertebrates and fish.

The ideal value of KH in a saltwater aquarium is 7-10 dKH° and for a planted freshwater aquarium is 3-7 dKH°.

Because of the importance of KH, it is necessary to keep the proper KH level by testing it with an accurate test kit. ELOS AquaTest KH, as well as all the other titrimetric test kits of this line will grant very high precision thanks to several procedures like the use of calibrated droppers with constant and predefined drops of 0.05 ml each, the validation of our reagents through NIST (National Institure 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 60 test (with a standard level of 10 dKH)
  • "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 - Carbonate Hardness Reviews

    Average Rating
    (14 reviews)
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    of 2

    Elos test kits

    Reviewers Rating Unsatisfactory

    Posted: 10/27/2013 from CASPIAN, MI UNITED STATES
    1.0 5
    Experience Level: Intermediate

    Comments: I was not impressed with test kits from Elos , had to calculate kh/alk cannot get an exact reading .I will stick with salifert, much easier to get accurate reading. I will continue to use other Elos products though.

    Did you find this review helpful? Yes No

    great test kit

    Reviewers Rating Great

    Posted: 11/12/2009 from FREMONT, CA UNITED STATES
    4.0 5
    Experience Level: Expert

    Comments: I have used several test kits from API,Salifert to LaMotte and the Elos is IMO on par with the Lamotte. The only issue I have is that the color change from cyan to yellow is too subtle. I would have given it 5 stars if not for this. The test kits are dated which is a good thing. My last kit was API and was inaccurate and had no on it. You can also use 1/2 the measurements for testing and extend the life of the kit with the same accuracy.

    1 of 1 People found this review helpful, did you? Yes No


    Reviewers Rating Below Average

    Posted: 10/30/2009 from Corona
    2.0 5
    Experience Level: Intermediate

    Comments: This kit is probably accurate but trying to decipher a color change from cyan to yellow when the colors are so week is a pain. I think I will be sticking with Salifert, just as accurate and no guessing on weak color changes.

    1 of 1 People found this review helpful, did you? Yes No

    elos test kit

    Reviewers Rating Unsatisfactory

    Posted: 7/16/2009 from COLUMBIA, TN UNITED STATES
    1.0 5
    Experience Level: Intermediate

    Comments: just like the other test kits on the market thay all give diffrent readings i would not sugest to anybody (if ther was a co. that would just make a good test kit for all paramters of salt water you have to bye 6 diffrent ones to get the rite readings and then you have to send t to a lab to see f its right!!!!!!!!!!!!!! kevin

    0 of 2 People found this review helpful, did you? Yes No


    Reviewers Rating Great

    Posted: 4/18/2009 from NEW PORT RICHEY, FL UNITED STA
    4.0 5
    Experience Level: Intermediate

    Comments: I found the test kit instructions confusing at first but after a few times of testing, it became easier. Over all a very good product, with plenty of testing in each kit.

    Did you find this review helpful? Yes No

    Who do you believe

    Reviewers Rating Great

    Posted: 8/20/2008 from EDMOND, OK UNITED STATES
    4.0 5
    Experience Level: Intermediate

    Comments: I had been using Salifert test kits. I purchased ELOS CA, KH and MG kits because I heard the colors were easy to see. After using the kits, I find that ELOS are much easier to tell the change points. Results of CA and MG are very close to the Salifert tests. KH is way off from Salifert, so I am going to try a third kit to try to figure out which one is inaccurate.

    Did you find this review helpful? Yes No

    Great kit!

    Reviewers Rating Excellent!

    Posted: 5/20/2008 from LAGUNA HILLS, CA UNITED STATES
    5.0 5
    Experience Level: Intermediate

    Comments: Great test kit. Never can go wrong with elos!!! With the way the instructions read, you get a alk value in whole numbers. If you want more accuracy, all you have to do is double the amount of water, and then each drop is worth half as much!

    4 of 4 People found this review helpful, did you? Yes No

    High Quality

    Reviewers Rating Excellent!

    Posted: 4/12/2008 from AUSTIN, TX UNITED STATES
    5.0 5
    Experience Level: Beginner

    Comments: Very high quality and attention to detail. Results seem to be accurate. Very good quality control

    Did you find this review helpful? Yes No

    Excellent KH test kit

    Reviewers Rating Excellent!

    Posted: 2/21/2008 from LITTLETON, CO UNITED STATES
    5.0 5
    Experience Level: Intermediate

    Comments: This is the best KH test kit I've used. It's inexpensive, easy to use, easy to read and accurate. For most tests, the full 1 degree result is OK and can easily be converted to 1/2 degree. I now use one test for both my tank and my calcium reactor.

    1 of 1 People found this review helpful, did you? Yes No

    Not what I thought.

    Reviewers Rating Average

    Posted: 2/12/2008 from FL UNITED STATES
    3.0 5
    Experience Level: Expert

    Comments: This is a O.K. kit been using sailifert kits for years figured I'd give it a shot. Not what I was expecting. I thought it would be more accurate and read in smaller scales. It in my opinion just gives whole numbers 9-10-11 not very specific don't know if I'm boarder line 9 when it says nine or closre to 10 would like more specific accuracy. Test vile dosn't match up with the glass vial you draw water with. 5ml on the glass vial is under the mark of the water line you draw with the measuring device. Very confusing for a kit that is suposed to be high end. Moer like the Hagen kits and the API kits. I'll just use this kit as a reference along with my others good back up kit not the only kit you'll ever need.Just O.K.

    6 of 7 People found this review helpful, did you? Yes No

    of 2
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