Hannah Ultra Low Phosphorus

jda · 12/29/2014, 05:06 PM

I just ran the same test 5 times - tank water in 1 vial and the packet mix in the other one.

I got 61, 0, 41, 36 and 29. What am I supposed to do with this?

I wish that I never would have tested it.

slief · 12/29/2014, 05:18 PM

LOL... First off, did you make sure the vials were perfectly clean after you filled them? Secondly, did you make sure to get all the regent out of the packet? Those packets can be a bit of a pain to empty. Also, did you make sure the regent was well mixed and completely dissolved? Did you also make sure not to shake too hard so that you don't get air bubbles in the water? Air bubbles will effect the test accuracy. Did you make sure to clean the test vials of any water spots and finger prints before putting them in the photometer? Lastly, you need to do the math to convert to Po4.

This is they way I do my test. Like you, I fill both vials to the line with tank water. Some will frown on this but I've tested both ways using one vial vs two and got essentially the same results. It's been said that for best results only one vial should used due to differences in the glass but I've found it difficult to get the regent properly mixed and the vial cleaned before the tester shuts off. Anyhow, I add regent to one of the vials and begin gently shaking it and swirling it until the regent is completely dissolved while being careful not to get air bubbles in the water. I then clean both vials very well to make sure they are spotless. Next I put the vial with water only into the photometer. Once it's done taking it's reading, I swap the vial and let it do it's countdown.

I then take the result and multiply it by 3.066 and then divide by 1000 to get Po4 number in PPM which is the number we are ultimately after. I've found my ULR tester to be very consistent and accurate.

If your numbers are that inconsistent, you are either not mixing properly or completely, not cleaning the vials well between use, not cleaning the outside of the vials well before you place them in the tester, have air bubbles in the water, are using expired tests or possibly have a bad batch of regents which isn't unheard of but the least likely scenario unless these are old regents.

acesq · 12/29/2014, 05:36 PM

You do need to be very careful about all of the things Scott mentions. If so, then for me at least the test is very repeatable.

I do go a step further and use just one vial because I am concerned about the differences in opacity of the vials. The timer on my egg must be set a bit longer than Scott's though because I have never had any trouble getting the reagent to dissolve in the allotted time.

slief · 12/29/2014, 05:37 PM

Quote:

Originally Posted by acesq

You do need to be very careful about all of the things Scott mentions. If so, then for me at least the test is very repeatable.

I do go a step further and use just one vial because I am concerned about the differences in opacity of the vials. The timer on my egg must be set a bit longer than Scott's though because I have never had any trouble getting the reagent to dissolve in the allotted time.

I just mix slowly I guess. I've managed both ways but between mixing and cleaning the vial of finger prints, I've missed the window on more than one occasion.

outssider · 12/29/2014, 07:09 PM

you should be able to get at least 2.5 minutes while the unit says c2 then if you press and hold the button you can get another 3 minutes on the 3 minute count down timer. If you can't get the job done in 5.5 minutes.....well ...you need to practice a little.

this is how I do it....
cut the reagent pack and have it ready to pour first.
use one vial but fill both. do the test with one vial then double check several times by using the two vial method . don't use new reagent, just switch back and forth the vials several times doing the test. the reacted sample will stay accurate for some time. I have tried it as much as a half hour later and still get the same readings.

every time a test with the same samples my numbers are usually within 5ppb

12/29/2014, 05:06 PM	#1
jda Dogmatic Dinosaur Join Date: Feb 2004 Location: Boulder, CO Posts: 6,256	Hannah Ultra Low Phosphorus I just ran the same test 5 times - tank water in 1 vial and the packet mix in the other one. I got 61, 0, 41, 36 and 29. What am I supposed to do with this? I wish that I never would have tested it.

12/29/2014, 05:18 PM	#2
slief RC Sponsor Join Date: Sep 2009 Posts: 14,173	LOL... First off, did you make sure the vials were perfectly clean after you filled them? Secondly, did you make sure to get all the regent out of the packet? Those packets can be a bit of a pain to empty. Also, did you make sure the regent was well mixed and completely dissolved? Did you also make sure not to shake too hard so that you don't get air bubbles in the water? Air bubbles will effect the test accuracy. Did you make sure to clean the test vials of any water spots and finger prints before putting them in the photometer? Lastly, you need to do the math to convert to Po4. This is they way I do my test. Like you, I fill both vials to the line with tank water. Some will frown on this but I've tested both ways using one vial vs two and got essentially the same results. It's been said that for best results only one vial should used due to differences in the glass but I've found it difficult to get the regent properly mixed and the vial cleaned before the tester shuts off. Anyhow, I add regent to one of the vials and begin gently shaking it and swirling it until the regent is completely dissolved while being careful not to get air bubbles in the water. I then clean both vials very well to make sure they are spotless. Next I put the vial with water only into the photometer. Once it's done taking it's reading, I swap the vial and let it do it's countdown. I then take the result and multiply it by 3.066 and then divide by 1000 to get Po4 number in PPM which is the number we are ultimately after. I've found my ULR tester to be very consistent and accurate. If your numbers are that inconsistent, you are either not mixing properly or completely, not cleaning the vials well between use, not cleaning the outside of the vials well before you place them in the tester, have air bubbles in the water, are using expired tests or possibly have a bad batch of regents which isn't unheard of but the least likely scenario unless these are old regents. __________________ Director Customer Support Royal Exclusiv USA For All Royal Exclusiv & Bubble King questions please refer to our Sponsor forum: http://www.reefcentral.com/forums/fo...play.php?f=745 Current Tank Info: 480G display mixed reef, 90G sump, 90G refugium, 60G display refugium. Check out my build thread: http://www.reefcentral.com/forums/showthread.php?t=1783476

12/29/2014, 05:36 PM	#3
acesq Registered Member Join Date: Mar 2010 Location: Calabasas, CA Posts: 1,501	You do need to be very careful about all of the things Scott mentions. If so, then for me at least the test is very repeatable. I do go a step further and use just one vial because I am concerned about the differences in opacity of the vials. The timer on my egg must be set a bit longer than Scott's though because I have never had any trouble getting the reagent to dissolve in the allotted time. __________________ Current tank: 340g AGE peninsula

12/29/2014, 07:09 PM	#5
outssider Registered Member Join Date: Nov 2009 Location: Reseda, Ca. Posts: 1,717	you should be able to get at least 2.5 minutes while the unit says c2 then if you press and hold the button you can get another 3 minutes on the 3 minute count down timer. If you can't get the job done in 5.5 minutes.....well ...you need to practice a little. this is how I do it.... cut the reagent pack and have it ready to pour first. use one vial but fill both. do the test with one vial then double check several times by using the two vial method . don't use new reagent, just switch back and forth the vials several times doing the test. the reacted sample will stay accurate for some time. I have tried it as much as a half hour later and still get the same readings. every time a test with the same samples my numbers are usually within 5ppb