motti November 22, 2014 Share November 22, 2014 Hi, I am getting different readings form my CA Hanna checker, anywhere from 500-570 (i know its a bit high... that's another mystery.. last week it was 465, didn't add new salt water or anything). Does any one have any experience with those meters? anyone got similar readings? those The first reading i took, was 570, which seemed really high, so i tried another test, and it came 510, tried another one and it came 525. followed the instruction and used ro/di water. Link to comment Share on other sites More sharing options...
miggs76 November 23, 2014 Share November 23, 2014 You really need to get exactly.1 ml of water in the sample. If you are off by even a couple hundredths your readings will not be accurate. That's my experience with this checker. Link to comment Share on other sites More sharing options...
motti November 23, 2014 Author Share November 23, 2014 You really need to get exactly.1 ml of water in the sample. If you are off by even a couple hundredths your readings will not be accurate. That's my experience with this checker. Ah that sucks any tips on doing that? Link to comment Share on other sites More sharing options...
bqq100 November 23, 2014 Share November 23, 2014 Has anyone ever tried diluting 1ml of sample in 100ml of DI water and then filling the vial up with 10.1ml? That should make the dilution more accurate than trying to measure out exactly .1ml. Link to comment Share on other sites More sharing options...
menglish November 23, 2014 Share November 23, 2014 I use a 1ml syringe. Fill it to exactly the 1ml mark then use the plunger to dispense 0.1ml (ie from 1 to 0.9 or from 0 to .1, depending on how the syringe is labeled). Having said that, i too have been seeing very strange results the the Ca checker. One day I got a reading of 473, 24 hrs later, re took the test and got 499 and did not add anything to the tank. go figure. Link to comment Share on other sites More sharing options...
zygote2k November 23, 2014 Share November 23, 2014 simple solution- go back to typical reagent kits like Salifert. Link to comment Share on other sites More sharing options...
motti November 23, 2014 Author Share November 23, 2014 simple solution- go back to typical reagent kits like Salifert. Seems like I might... I am really happy with the other 2 color meters I got but this one is just too touchy. I've been filling it up to the 1ml market, pushing it down to .9 so only dispensing .1 ml Link to comment Share on other sites More sharing options...
wangspeed November 23, 2014 Share November 23, 2014 I get consistent and accurate readings from mine now but I needed two major changes. One is a .5ml syringe with a tapered tip attached and ensuring micro drops at the end of a .1ml sample are dispensed into the vial. The second is using lab grade Hanna RODI. I probably wouldn't recommend the kit to folks that don't already have it, but if you do, make these two changes and you should be good. If you don't, you are almost always doomed to readings that are way too high. -- Warren Link to comment Share on other sites More sharing options...
motti November 23, 2014 Author Share November 23, 2014 I get consistent and accurate readings from mine now but I needed two major changes. One is a .5ml syringe with a tapered tip attached and ensuring micro drops at the end of a .1ml sample are dispensed into the vial. The second is using lab grade Hanna RODI. I probably wouldn't recommend the kit to folks that don't already have it, but if you do, make these two changes and you should be good. If you don't, you are almost always doomed to readings that are way too high. -- Warren Where can I find those .5ml syringes? Looked in Amazon but no luck Link to comment Share on other sites More sharing options...
wangspeed November 23, 2014 Share November 23, 2014 I gave hanna a hard time about it and they sent me the syringe and small bottle of Hanna water. You can get the water from BRS. The syringes are forever insulin I think. Ask Hanna. If that doesn't pan out, search google for 1/2 ml syringe. They are hard to look for since slashes and periods are not indexed and places like Cole Parmer sell in bulk quantities. -- Warren Link to comment Share on other sites More sharing options...
Origami November 23, 2014 Share November 23, 2014 I've had my Hanna calcium checker on the shelf for years. I was getting the same high / finicky readings and wrote Hanna. They sent me a new testing protocol and asked me to try it. But, to be honest, I just put the checker on the shelf and continued to use my boxed test kits (like Salifert, Red Sea Pro, and API). Here's the modifed procedure that I received back then. Try it if you want: Modified Hanna Ca Checker Procedure (3/2013) 1. Add 1.0 mL of sample water to one of the sample cuvettes using the syringe with the green plunger. 2. Use the dropper to fill the cuvette to the 10 mL mark with deionized water. Replace the cap and invert the cuvette 3-5 times to mix and set to the side. 3. Turn the meter on by pressing the button, all segments will be displayed. When the display shows “Add”, “C1” with “Press” blinking, the meter is ready. 4. Add 1 mL of Reagent A to the cuvette using the syringe with the white plunger. Use the dropper to add 8 mL of deionized water to the cuvette. Replace the cap and invert 3-5 times to mix. 5. Place the cuvette into the meter, close the lid and press the button. When the display shows “Add”, “C2” with “Press” blinking the meter is zeroed. 6. Remove the cuvette from the meter and unscrew the cap. Fill the syringe with the green plunger to the 1 mL mark with sample from the first cuvette and discard. Fill the syringe again with 1 mL of sample water and add it to the second cuvette. 7. Add 1 packet of Reagent B to the second cuvette. Replace the cap and shake vigorously for 15 seconds or until the powder is completely dissolved. Allow air bubbles to dissipate for 15 seconds before taking a reading. 8. Place the cuvette back into the meter and close the lid. Press the button. The meter displays calcium concentration in ppm. Link to comment Share on other sites More sharing options...
motti November 24, 2014 Author Share November 24, 2014 Will try that tomorrow afternoon Link to comment Share on other sites More sharing options...
motti November 24, 2014 Author Share November 24, 2014 Reached out to Hanna Instruments yesterday, they got back to me this morning. they sent me an updated instruction sheet: https://www.dropbox.com/s/wsjm00d7d9tm6hh/HI%20758%20TIPS.doc?dl=0 and they said they will send me one battle of RO/DI water, and the .5ml syringe. Link to comment Share on other sites More sharing options...
Origami November 25, 2014 Share November 25, 2014 Thanks, Motti, for posting that. Here's a PDF version for people. It is slightly different than what they sent me a while back. I have to assume that this new procedure is "new and improved?" HI 758 TIPS.pdf Link to comment Share on other sites More sharing options...
menglish November 26, 2014 Share November 26, 2014 Thank you so much for the info. I will also try this protocol Link to comment Share on other sites More sharing options...
wangspeed November 26, 2014 Share November 26, 2014 Despite the initial issues, this is still my preferred method of measuring CA, short of sending it to AWT or Triton. It is inline with my AWT tests, so I am happy with it, you just need to be careful. The .1ml sample and perfect RODI water are the keys to success. I detest dealing with color changing tests. I'd rather do a color comparison if I had to choose. Here's their youtube video on using this meter. It's quite good. This is how I learned about the packet into funnel trick. I especially like how she plunks the IO sample down at the end. https://www.youtube.com/watch?v=LGjpicL6hTk Link to comment Share on other sites More sharing options...
Origami November 26, 2014 Share November 26, 2014 Despite the initial issues, this is still my preferred method of measuring CA, short of sending it to AWT or Triton. It is inline with my AWT tests, so I am happy with it, you just need to be careful. The .1ml sample and perfect RODI water are the keys to success. I detest dealing with color changing tests. I'd rather do a color comparison if I had to choose. Here's their youtube video on using this meter. It's quite good. This is how I learned about the packet into funnel trick. I especially like how she plunks the IO sample down at the end. Thanks for the endorsement, wangspeed. It helps to know someone here that is using the meter successfully. Maybe I'll give it a try again. The original testing protocol was very sensitive. Can you confirm that you're using the protocol provided by Hanna in post #14 above? I use the same funnel method for the phosphorus checker. It's a great tip for those that don't already know about it. Link to comment Share on other sites More sharing options...
wangspeed November 26, 2014 Share November 26, 2014 (edited) I skimmed the doc. I don't see anything about diluting 1ml into 10ml and then sampling again from that. I just use the .5ml syringe and plunge from .4 to .3 ml with the tapered tip, ensuring that if there is a micro drop at the end to shake it off into the vial. If I remember I may try to make a video the next time I do the test. -- Warren Edited November 26, 2014 by wangspeed Link to comment Share on other sites More sharing options...
Origami November 26, 2014 Share November 26, 2014 I skimmed the doc. I don't see anything about diluting 1ml into 10ml and then sampling again from that. I just use the .5ml syringe and plunge from .4 to .3 ml with the tapered tip, ensuring that if there is a micro drop at the end to shake it off into the vial. If I remember I may try to make a video the next time I do the test. -- Warren Interesting. It sounds like you may be performing the procedure that Hanna sent me over a year ago. I copied that email in Post #11. It'd different than the one that they recently sent to Motti, but does contain a step where you dilute the sample and resample from that. There is an implicit dilution in the new procedure, though, when they only take a 0.1ml sample of tankwater and use that. The new procedure may be a tad easier to perform, too, since it doesn't rely on measuring out an odd 8ml sample of RO/DI water. The two procedures are pretty much equivalent. Link to comment Share on other sites More sharing options...
motti November 26, 2014 Author Share November 26, 2014 I think it's possible that my readings are off because of my RO/DI water, and the fact that I didn't use the tip on the syringe. Going to try again once the water and the syringe arrives from Hanna Instruments. Link to comment Share on other sites More sharing options...
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