No Alk Reagent

Jason Collins · Feb 14, 2018

Does everyone feel like their hanna checker for alk is accurate? I need to get a salifert test kit to check it out but I feel like I basically always get 7.6 - 7.8 on mine. No matter how much Alk I dose... No matter if I check it right before or right after a 15% water change. Then the other day i tested it and it read 6.4 ... i said there is no way my tank is only 6.4 so I retested and bam 7.7 again. I only got a higher reading of 8.4 one time. I feel like for the price it should be more accurate. But again... I havent tested with another tester just yet to verify it. Maybe my tank is just running really low alk for some reason for months. My calcium and magnesium i test with salifert and my readings always seem to be good. But alk is ALWAYS low with my hanna checker.

I bought my replacement reagants straight from Hanna.

Also I always wonder how to get an accurate reading for the amount of reagant we add to the test vial... Salifert syringe explains to pull the black rubber part right to the line. The extra air pocket is supposed to be there to account for the reagent that is in the point of the syringe. With hanna I have the orginal syringe that has a flat black rubber just like salifert, then with the replacement reagent I bought it has an extended long rubber piece that looks to be the shape of the point on the syringe. So i was curious if everyone draws the reagent to the top line, or if they just draw the rubber part back to the line like salifert says to do with theirs.

Hanna Instruments · Feb 14, 2018

Jason Collins said:
Does everyone feel like their hanna checker for alk is accurate? I need to get a salifert test kit to check it out but I feel like I basically always get 7.6 - 7.8 on mine. No matter how much Alk I dose... No matter if I check it right before or right after a 15% water change. Then the other day i tested it and it read 6.4 ... i said there is no way my tank is only 6.4 so I retested and bam 7.7 again. I only got a higher reading of 8.4 one time. I feel like for the price it should be more accurate. But again... I havent tested with another tester just yet to verify it. Maybe my tank is just running really low alk for some reason for months. My calcium and magnesium i test with salifert and my readings always seem to be good. But alk is ALWAYS low with my hanna checker.

I bought my replacement reagants straight from Hanna.

Also I always wonder how to get an accurate reading for the amount of reagant we add to the test vial... Salifert syringe explains to pull the black rubber part right to the line. The extra air pocket is supposed to be there to account for the reagent that is in the point of the syringe. With hanna I have the orginal syringe that has a flat black rubber just like salifert, then with the replacement reagent I bought it has an extended long rubber piece that looks to be the shape of the point on the syringe. So i was curious if everyone draws the reagent to the top line, or if they just draw the rubber part back to the line like salifert says to do with theirs.

Our HI772 dKH Alkalinity Checker has an accuracy statement of ±0.3 dKH ±5% of reading. The major advantage of using a colorimeter, or digital test, is you can measure accuracy without subjective human error (so long as instructions are followed). Other chemical test kit brands may claim to have an accuracy statements but you cannot quantify inaccuracies brought about by judging color changes. A big advantage for using a Hanna Checker is there little subjectivity in the process of analysis. We have a very simplified alkalinity test, there are no color changes to determine or drops to count. This leads to a higher rate of repeatable success and precision.

If you are ever concerned with the accuracy of your Checker, you can purchase a standard to make sure the device is preforming within its accuracy statement.

http://hannainst.com/hi772-11-marine-alkalinity-dkh-checkerr-hc-calibration-set.html

When using our HI772 and HI755 marine alkalinity Checkers the liquid reagent is administered with a 1ml syringe and tip. When the tip is attached to the syringe, all of the reagent will remain in the tip leaving the syringe portion empty. If the tip is not attached, then there will be a small space of air between the 1ml of reagent and the last mark on the syringe. When using the syringe, always bring the black rubber stopper to the last full line, not the reagent. Matching the reagent to the last fill line will result in overdosage of reagent.

Also visit our blog to make sure you are following our 8 checker best practices such as indexing the cuvette in the same position every time, removing any air bubbles, finger prints or smudges and using separate pipettes/syringes for freshwater and saltwater.