Hanna phosphate checker reliable?

[bluefunelement]

Anyone have one and able to confirm it is accurate and easy to use/calibrate?

http://premiumaquatics.com/store/merchant.mvc?Screen=PROD&Store_Code=PA&Product_Code=HI-713&Category_Code=

[Coral Hind]

I have one and it is very easy to use. One key thing to remember is to make sure the test tube stays clean as dirt or finger prints can give you a higher then true reading.

[Jan]

I have one. It's easy to use. Seems to be accurate.

[scott711]

I have one and it is very easy to use. One key thing to remember is to make sure the test tube stays clean as dirt or finger prints can give you a higher then true reading.

 

+1

[sachabballi reef]

+1 on being obsessive with keeping the vial pristine....no finger prints etc.....

i love mine...

[Origami]

Yes, both accurate and easy to use. To add one more thing to what others have said, be sure that you keep an eye on the reading as the timer counts down. When the timer expires, the reading is displayed for ten seconds, after which the unit automatically shuts down. It's easy to miss if you get distracted.

 

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[bluefunelement]

Does everyone use glass vials and clean with RO water? My pre DI faucet has a TDS of 4 so I clean most vials with that.

[DDiver]

does everyone use only use one vial?i find that if you try to use one vial ,it is almost impossible to get the reagent to dissolve completely before running out of time.What i do is i fill both the vials up and then i put reagent in one and shake it until it dissolves completely then i do the test making sure i don't let it sit for more than a couple minutes and seem to get pretty accurate readings.I also do it a few times with the same solution just to make sure.

[Hilary]

does everyone use only use one vial?i find that if you try to use one vial ,it is almost impossible to get the reagent to dissolve completely before running out of time.What i do is i fill both the vials up and then i put reagent in one and shake it until it dissolves completely then i do the test making sure i don't let it sit for more than a couple minutes and seem to get pretty accurate readings.I also do it a few times with the same solution just to make sure.

 

I use two vials as well because of the same issue. Glad I'm not the only one!

[Big Country]

First time I used mine I ran out of time and the unit shut off also, I used 2 vials to do the test again, guess they should have set that time a little longer when the instructions say to shake for 2 minutes and the unit shuts off after 2 minutes. I just got my unit from online for $53 shipped with 50 reagents.

[Origami]

Does everyone use glass vials and clean with RO water? My pre DI faucet has a TDS of 4 so I clean most vials with that.

 

I keep a squeeze bottle of RO/DI handy (on the shelf next to where I do most of my tests) and rinse all my vials.

 

does everyone use only use one vial?i find that if you try to use one vial ,it is almost impossible to get the reagent to dissolve completely before running out of time.What i do is i fill both the vials up and then i put reagent in one and shake it until it dissolves completely then i do the test making sure i don't let it sit for more than a couple minutes and seem to get pretty accurate readings.I also do it a few times with the same solution just to make sure.

 

I've run two vials before but prefer to run just one and to keep it aligned the same way in the tester as when the reference pass was completed. I've found that, in order for me to do just one vial, I need to open the pack of reagent first, creasing it so that I can pour it out smoothly and quickly after the reference pass is completed. This gives me around 90 seconds to shake the vial to dissolve the reagent.

[sachabballi reef]

so am I the onlyone that shakes it until it dissolves and then uses the read instantly button? I mean sometimes I use the count feature but most times after all these years I just do the dissolve and instant read

[Origami]

so am I the onlyone that shakes it until it dissolves and then uses the read instantly button? I mean sometimes I use the count feature but most times after all these years I just do the dissolve and instant read

 

I'm unaware of a "read instantly" button. There is a button, but you're supposed to hold it down until a 3-minute countdown timer starts. The reading is taken after that time (after the reagents have had a chance to react fully with the dissolved phosphate).

 

Here's a link to the manual:

http://www.hannainst.com/manuals/ist713_02_04_10.pdf

 

The measurement instructions say,

 

• Turn the meter on by pressing the button. After all the segments are displayed, “C.1”, “Add” appears with “Press” blinking, the meter is ready.

 

• Fill the cuvette with 10 mL of unreacted sample and replace the cap. Place the cuvette into the meter and close the meter’s cap.

 

• Press the button. When the display shows “Add”, “C.2” with “Press” blinking the meter is zeroed.

 

• Remove the cuvette, open it and add the content of one packet of HI 713-25 reagent. Replace the cap and shake gently for 2 minutes until the powder is completely dissolved. Replace the cuvette into the meter.

 

• Press and hold the button until the timer is displayed on the LCD.

 

• The instrument directly displays the concentration of phosphate in ppm. The meter automatically turns off after 10 seconds.

[Mountaineer]

Maybe he is thinking of the phosphate reader from Hanna and not the "checker".

[Origami]

Maybe he is thinking of the phosphate reader from Hanna and not the "checker".

Could be. But I thought you had to wait three minutes for both systems(?). You're probably right, after all, they did say, "after all these years." Since Hanna's Checkers have only been on the market for a few months, they're probably using Hanna's photometer rather than the less expensive colorimeter.

 

Both devices work on the same principle, I think: Measuring the amount of light absorbed at a particular wavelength both before and after the reagent is added. The difference in absorbtion is then used to calculate the phosphate level. Thus, it's important to give the reagent the chance to thoroughly react with the water before testing it. That's why Hanna makes us wait before taking the measurement.