Calcium Colorimeter HI758 Hanna Checker - Marine Water

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Calcium Colorimeter HI758 Hanna Checker - Marine Water

SKU: 206202
130 Review(s)
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  • use RO water to clean cuvettes!! By on 9/21/2017

    Just got an article from Hanna saying to clean the cuvettes with RO/DI water and NOT tap because the tap water has calcium in it!! So I thoroughly cleaned them with RO water and my high (542) reading went away and got my usual 480 reading!!! So use RO water to clean!
  • Consistent and easy to use. By on 8/14/2017

    I wish I had ignored reviews and purchased this earlier. Works great and easy to use. If you follow the instructions, the readings are consistent. I do not have the problems others have reported with high readings. I use RODI with TDS at 0 (up to 10tds) and have been continuing my testing with the previous trusted test kit. The readings are consistent with the old testkits.
  • Accurate if you have accurate sample By on 8/8/2017

    So, I found out immediately the pipette that Hanna includes in the kit isn't good. I switched to using a syringe and tip from my old Red sea test it and ended up getting accurate tests. I bought the calcium standards along with this meter and run a test using them before I test my tank and found the meter is 25ppm low, so I adjust accordingly. I use RO/ DI water not the distilled as suggested and get good results. So, if you have a good sample amount it's accurate. I like this meter and find it easier than counting drops.
  • Wildly Inaccurate By on 8/8/2017

    I've used quite a few of the Hanna checkers before, and overall, I've been pretty happy with them. They're good, and any of the complaints you see on here tend to focus on user error or difficulties with the dry packets. This test, however, leaves quite a bit to be desired.

    To use it, you fill a 10 mL vial with 9 mL of D2O and 1 mL of reagent. You shake it, use this to zero the meter, and then add 0.1 mL of your sample plus the reagent. Zero Point One. The first time I used this thing, I got a reading of 580 mg/L Ca. The water had just been tested in lab, and was 460 mg/L. Another test kit showed it to be about that, and certainly no 580 mg/L. A subsequent test with the Hanna meter then showed that the calcium level was 620 mg/L!!!!!!

    A big part of the problem goes to the sample size. You're only using 0.1 mL of sample, and relying on their relatively cheap micropippete to deliver it. There's so little sample in there that, heck, moisture collected on the outside of the pipette could nearly double the sample size (and thus the amount of calcium in the tank). You're also relying on the availability and quality of your D2O. If you don't have an RO system or something to produce at least deionized, you can't use this test kit, and if your system is a little aged... you're introducing a source of error.

    The advantage of the Hanna tests is that they're supposed to be easier, too. You put in your sample and reagent, mix them, get a good number. No counting drops, no comparing charts, no guessing "is it blue NOW?". This test is really quite complicated, and just relies on too small an amount to ever be accurate.
  • Dont BUY By on 8/5/2017

    very inaccurate
  • NOT ACCURATE By on 7/3/2017

    Bought this and was using it for several months. Could never recommend this product. I could not figure out why my calcium levels stayed the same (even high at 490/500) while magnesium and dKh dropped normally. Thought it might be my religious water changes (2x weekly 5%). Finally got suspicious and double checked using a sample of 470ppm calcium. Reading on a Seachem test AND Nyos was 470. Reading on Hanna ..... 550ppm. This is consistent at least. Reading on Seachem for my tank is at 410 and yet on Hanna, 480. Somehow I am getting almost exactly 70ppm too high every time. Don't waste the $50. NYOS does a great job with making color matching easy.
  • This is garbage By on 6/15/2017 it for free, at least I didnt pay for it lol
  • Accurate if you are very methodical By 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 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 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.