Calcium Colorimeter HI758 Hanna Checker - Marine Water

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Calcium Colorimeter HI758 Hanna Checker - Marine Water

63% Recommend this to a friend (78 of 124)

SKU: 206202
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Quick Overview

Redesigned with new 100 µL Pipette

Accurately check your reef tanks calcium level with the Hanna HI758 Calcium Checker.


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Product Questions

Is this the redesigned version with the new 0.1ml pipette?
Question by: Charles Weller on May 17, 2017 8:50:00 PM
These are indeed the new test kits with the .1 mL pipette included! We're working on getting an up-to-date photo on the website to reflect this.

Have a great weekend!
Answer by: Zack (Admin) on May 19, 2017 8:44:00 AM
From Hanna's official video (link attached) of this checker in 2016, it comes with a 0.1 ml pipette for adding the sample water. Does the checker sold at BRS comes with the pipette or green syringe? pipette shown at 0:50
Question by: Alex on May 18, 2017 3:25:00 AM
These are indeed the new test kits with the .1 mL pipette included! We're working on getting an up-to-date photo on the website to reflect this.

Have a great weekend!
Answer by: Zack (Admin) on May 19, 2017 8:59:00 AM
Are the reagent packets really that hard to open and get into the vials?

It seems that the biggest/only gripe about this unit in the reviews is that it uses a powder reagent and not a liquid.

Is it really that hard to open the packet and get all of the powder in the vial?
Question by: G on Apr 20, 2016 11:16:00 AM
Great question!
We do not have issue with the packets, As long as the packet is shaken to the the power into one corner, The flap is then cut and the packet folded to allow the power to fall down the crease in the packet we have not had issues ourselves.
Answer by: Connor (Admin) on Apr 26, 2016 1:37:00 PM
does the hanna checker come with the reagents, or do I need to order regents separate?
Question by: jeremy on Nov 26, 2013 8:23:00 AM
Hi Jeremy,
The Hanna Calcium Checker comes with enough reagent to do about 25 tests.
Answer by: Bulk Reef Supply on Nov 26, 2013 8:23:00 AM
I would like to buy a Hanna checker for nitrate please but can not see one on
Your web site
Question by: Stuart ray on Apr 10, 2014 10:50:00 AM
Hi Stuart,
They do not make a Nitrate checker. If/when they do though we will bring it in.
Answer by: Bulk Reef Supply on Apr 10, 2014 10:50:00 AM

Full Details


Three simple steps to results. The Hanna Calcium Checker bridges the gap between simple chemical test kits and professional instrumentation. Accurate, affordable and easy to use. First, zero the instrument with your water sample. Next, add the reagent. Last, place the vial into the Hanna Calcium Checker, press the button and read the results. Done.

Easier to use and more accurate than chemical test kits and is much easier to use. 

Tips for accurate results:

  • Use distilled water whenever possible
  • Make sure testing vials are clean of any debris
  • Vials must be dry on the outside with no fingerprints
  • Violent shaking will cause microbubbles that can affect the reading
  • Do not let the sample sit too long before taking a reading


New MiniPipette - The new minipipette has a 2-stage plunger that will let you accurately dispense your 0.1mL tank water sample. The pipette is spring loaded and will allow you to retreive and dispense 100 µL. Just attach the pipette tip, and press the button down until it stops the first time. Then place the tip into your tank water sample and slowly let the plunger spring back up. Move the pipette to your testing vial, and press the plunger down to the first stop to dispense the liquid it took in. 


Dedicated to a single parameter - Designed to work with HANNA's liquid reagents. Uses 10 mL glass cuvettes.


  • Range: 200 to 600 ppm
  • Resolution: 1 ppm (mg/L)
  • Precision: ±6% of reading
  • Light Source: LED @ 610 nm
  • Light Detector: Silicon photocell
  • Environment: 0 to 50°C (32 to 122°F); RH max 95% non-condensing
  • Battery Type: (1) 1.5V AAA
  • Auto-off: After 10 minutes of non-use and after read
  • Dimensions: 81.5 x 61 x 37.5 mm (3.2 x 2.4 x 1.5")
  • Weight: 64 g (2.25 oz.)
  • Method: Adaptation of the zincon method

Weighing a mere 65 g (2.3 oz.), the Checker®HC easily fits into the palm of your hand or pocket.Use for quick and accurate on the spot analysis. Single button operation: Zero and Measure Operated by a single AAA battery.



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  • This is garbage By Mark on 6/15/2017 it for free, at least I didnt pay for it lol
  • Accurate if you are very methodical By Robert on 5/14/2017

    I get consistent results if I'm very careful. Because of the precision required to get an accurate result I do test again to see if I made an error if I get a reading out of the norm. I think the very small sample is what causes the issues in most cases. Hanna should make this tester less sensitive to user error.
  • Works well By Sparky on 5/3/2017

    I find that the kit works well and is consistent. I noticed a lot of very poor reviews for this product and that it consistently measures high. My first few readings were high but I was not following th directions perfectly. Also, I use distilled water rather than my RODI water and that bings the reading down by about 50ppm. So at this point I am satisfied with the product,
  • Terrible inconsistency By Eric on 4/23/2017

    I have the alkalinity checker and this Ca checker. While the alk checker is great, this thing is junk. Always tests way too low. Save your money and get the Red Sea or Salifert kits. They take more effort to use, but my reef is worth it.
  • Don't waste your money By Deborah on 4/3/2017

    While I love the other Hanna Checkers, the Calcium tester reads false. I have readings that are through the roof and just about pulled my hair out trying to figure out my tank's wacky chemistry until I read online all the other complaints. I then pulled out my Red Sea test kit and checked my Calcium three times and all three were in the normal range.
    Do yourself a favor and skip the Hanna Calcium checker.
  • High Readings By Alex on 3/29/2017

    The sheer number of complaints of high readings is no coincidence and defies the suggestion of user error. I've used this tester a dozen times and every time the readings are 75-100ppm high. Id almost be willing to accept that and simply deduct that amount, but the test readings are never consistent either. For instance, immediately after a water change, I got a reading of 500ppm and a week later before I was going to do my water change I got a reading of 540. I'm not dosing.
  • Don't buy it By John on 3/15/2017

    Test come out alway above 520 ppm wast my money don't by it
  • Do not buy!! By RobertP on 3/13/2017

    I have a little trouble with colors so was not sure I was reading my red sea tests correctly. So i bought this hanna and I still dont! It consistently reads 580 and i reran the test 4 times. My red sea is constantly at 400 and 420. Since I am not dosing yet and doing weekly water changes it tells me rhis thing is junk. Im going to try it again and call hanna because this is $50 wasted.
  • Not worth buying By Joshua on 10/13/2016

    I have a couple other Hannah checkers which work flawlessly the precise they're accurate and you can check them against other test kits with out any difference you can repeat the tests and get for the most part the same exact numbers however ....
    I'm a medical professional I know how to draw up exact amounts of fluids and titrate I have followed the Hannah directions for the calcium meter exactly to a T and I cannot get the meter to reproduce The same test values ever . I took a sample of water and a clean sterile syringe filled up Both cravats and ran the test twice each one when compared to the Red Sea pro said the calcium was somewhere between 50 and 75 ppm higher than what the Red Sea showed . If it was five or 10 ppm that's not a big deal I could live with that but 50 or 75 ppm could theoretically mean the death of prized corals or the starvation of prize corals that I have worked very hard to keep alive.
    That being said if you're looking at other Hannah checkers bite the bullet because they're worth it but I would steer clear of the calcium and a checker and use a traditional titration such as the Red Sea, Nyosor even an API kit .
  • don't trust this checker By jason on 9/29/2016

    i do not dose my tank at all this checker one day give me 380 reading the next day give me 530 the third day 460 i m going crazy with this thing do not buy it
  • Works as advertised By Josh on 9/17/2016

    I haven’t run into any of the issues the others have. I can perform this test in a couple of min. and it’s accurate. I’ve compared it to other tests (even Triton Labs) and it has been within a few points. I’ve also have not seen inconsistencies between tests.
    I prefer this much more than trying to read colors
  • Not accurate By Mark on 8/29/2016

    This test takes almost as long as using titration via Red Sea's test and seems to read higher than Red Sea (60-80ppm higher). The sample size of tank water 0.1ml is way to small. if your off by a drop, your readings are skewed. I love their Alkalinity checker though!!!