Salifert Magnesium Please HELP!! three question driving me crazy

One fish · 05/13/2015, 12:03 AM

Hello RC. I have the Salifert Magnesium test kit and I am stuck on the last step... drawing the MG-3 into the syringe. I would love any advice! If you have the test kit and can check this for me I would really appreciate it.

The directions state...
Draw into this MG-3 reagent until the lower end of the black syringe part is at the 1.00 ml mark. Ensure that during this that the plastic tip is submerged in the reagent to avoid that air bubbles are withdrawn instead of liquid.
An air layer between the liquid and the piston is normal. This is air which was present between the end of the tip and the piston, this will not influence the result.

uploadfromtaptalk1425848789783.jpg

So my question is When I draw back the liquid, what is the lower end of the black syringe part? should I judge it looking at the tip up or tip down. I attached a picture and am wondering if this is the correct way to start.

Where should the liquid start? Some people say 7.5 and others say right above 8. In the picture it starts about the 8.

If i take the pink tip off can i just draw back the fluid to exactly 0?

I have googled and researched and cannot find the answer. Can anyone give me detailed instructions on how to do this.

Tarawa · 05/13/2015, 02:30 AM

the way your pic is showing it is the way I always do it

LinkinReef · 05/13/2015, 03:02 AM

I do it just like its in your picture.

downbeach · 05/13/2015, 04:03 AM

Your picture is accurate, the space(air) that is between the top of the fluid and the bottom of the black part of the plunger is equal to the amount of fluid that is in the tip itself. You will also use the black part, (not the top of the fluid), to determine your reading, since that will indicate the amount of fluid it took to get the end point color, which includes the fluid that is in the tip.

homer1475 · 05/13/2015, 05:02 AM

Quote:

Originally Posted by downbeach

Your picture is accurate, the space(air) that is between the top of the fluid and the bottom of the black part of the plunger is equal to the amount of fluid that is in the tip itself. You will also use the black part, (not the top of the fluid), to determine your reading, since that will indicate the amount of fluid it took to get the end point color, which includes the fluid that is in the tip.

+1

The Red Sea kits are also like this, drove me nuts trying to figure out why the liquid wasn't at the 1ml mark. Red Sea has a youtube video on how exactly to do the test, as well as how, and when to determine the color change(some of the titration tests aren't real easy to determine when the color actually changes, or how dark the color change is).

SassyAngel111 · 05/13/2015, 05:31 AM

there is a youtube for the salifert test http://www.bing.com/videos/search?q=...D59932204E1D24 Hope this somewhat helps

Kaidman · 05/13/2015, 07:37 AM

Funny, I just got my salifert kits last week and did the same test this weekend. I had the same question, it looked weird. The bubble ended up right around 0.8 for me also. Glad I wasn't doing something wrong!

The test is still accurate as long as you start the black portion right at 1.0. You will have added the same amount of the reagent to the water if you have a bubble or not. The bubble takes up the same amount of space once you get the reaction to occur. It just messes with your brain...

Sk8r · 05/13/2015, 01:06 PM

If you look at it as a basic question of 'how large is the fluid chamber,' its boundary is the bottom portion of the black plunger-seal.

disc1 · 05/13/2015, 01:54 PM

If you realize that you're only concerned with the change in the position of that piston as a measure of how much reagent you've delivered, you'll see that it doesn't matter as long as you take your reading from the same point. I like to use the very tip of the plunger because it is easiest to see. But I've had syringes (not from a Salifert kit) that had little black O-rings on them and that was even easier to see so I used that.

One fish · 05/14/2015, 11:33 AM

I really really appreciate the feedback. So my black spacer is in the correct starting point, got it.
The big problem that I am having is that the starting line of the liquid changes every time I draw back. It is not consistent. I drew a total of three times and received three different results. The first time was 8.6. The second time I draw it is 8.2(as shown in the picture) and the last time is even on 9ml. Can anyone compare this to their own kit and tell me where theirs starts?

Sk8r · 05/14/2015, 11:43 AM

Push the plunger all the way to the bottom (point downward) when starting to draw fluid, then pull up (learning how to do this one-handed is a learning curve). Pull up until the bottom of the black hits the 0. Ignore the air space. That's allowed for by the originating lab's chart.

To get a good view, set the vial on a white surface while dripping reagent in---this lets you see the reaction clearly: especially important if you have a colorblindness issue.

You will note that as you approach a point of reaction, you will see a 'flash' of color that immediately goes away. This flash tells you you are approaching the reaction point. Another few drops will do it.

In reactions like the alkalinity test that don't require an elaborate timed mixing procedure, you can speed the tests by watching for that flash as you rapidly add drops, and as you do see it, slow way down so that you don't miss the reaction point.

You can use your log as a reference. If last week the reaction point was at the place on the chart that's 8.3, and you're pretty sure you're in that territory this week, you know that you will have quite a lot of the test where you can add VERY rapidly. As you get closer to 8.3 territory, you slow down drop by drop and catch your reaction point. I know, it's cheating. But it still gives a result.

disc1 · 05/14/2015, 11:55 AM

Quote:

Originally Posted by One fish

I really really appreciate the feedback. So my black spacer is in the correct starting point, got it.
The big problem that I am having is that the starting line of the liquid changes every time I draw back. It is not consistent. I drew a total of three times and received three different results. The first time was 8.6. The second time I draw it is 8.2(as shown in the picture) and the last time is even on 9ml. Can anyone compare this to their own kit and tell me where theirs starts?

Make sure the tip isn't coming up out of the fluid while you draw it up letting air bubbles in.

Also, make sure the tip is on securely so no air bubbles are sneaking in that way.

In the end, as long as there is some fluid left in the syringe when you're done it shouldn't make a difference if the air pocket was a little larger or smaller. You're only concerned with the change in it's position.

05/13/2015, 12:03 AM	#1
One fish Registered Member. Join Date: Oct 2014 Location: Springfield Va Posts: 297	Salifert Magnesium Please HELP!! three question driving me crazy Hello RC. I have the Salifert Magnesium test kit and I am stuck on the last step... drawing the MG-3 into the syringe. I would love any advice! If you have the test kit and can check this for me I would really appreciate it. The directions state... Draw into this MG-3 reagent until the lower end of the black syringe part is at the 1.00 ml mark. Ensure that during this that the plastic tip is submerged in the reagent to avoid that air bubbles are withdrawn instead of liquid. An air layer between the liquid and the piston is normal. This is air which was present between the end of the tip and the piston, this will not influence the result. uploadfromtaptalk1425848789783.jpg So my question is When I draw back the liquid, what is the lower end of the black syringe part? should I judge it looking at the tip up or tip down. I attached a picture and am wondering if this is the correct way to start. Where should the liquid start? Some people say 7.5 and others say right above 8. In the picture it starts about the 8. If i take the pink tip off can i just draw back the fluid to exactly 0? I have googled and researched and cannot find the answer. Can anyone give me detailed instructions on how to do this.

05/13/2015, 03:02 AM	#3
LinkinReef Registered Member Join Date: May 2011 Posts: 987	I do it just like its in your picture. __________________ 34g

05/13/2015, 05:31 AM	#6
SassyAngel111 Registered Member Join Date: May 2006 Location: Phoenix, Az Posts: 167	there is a youtube for the salifert test http://www.bing.com/videos/search?q=...D59932204E1D24 Hope this somewhat helps __________________ I can resist anything but temptation Current Tank Info: 56gl. column tank, around 45lbs of rock, 2 1/2" sand, lights Oceanrvive 120w LED's, Maxi-jet 900, Eshopps PF800 overflow box, Eshopps R-100 refugium, skimmer Eshopps s120 Last edited by SassyAngel111; 05/13/2015 at 05:40 AM.

05/13/2015, 01:06 PM	#8
Sk8r RC Mod Join Date: Feb 2006 Location: Spokane WA Posts: 34,628 Blog Entries: 55	If you look at it as a basic question of 'how large is the fluid chamber,' its boundary is the bottom portion of the black plunger-seal. __________________ Sk8r Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low. Current Tank Info: 105g AquaVim wedge, yellow tang, sailfin blenny,royal gramma, ocellaris clown pair, yellow watchman, 100 microceriths, 25 tiny hermits, a 4" conch, 1" nassarius, recovering from 2 year hiatus with daily water change of 10%.

05/13/2015, 01:54 PM	#9
disc1 -RT * ln(k) Join Date: Sep 2010 Location: Little Rock Posts: 9,705	If you realize that you're only concerned with the change in the position of that piston as a measure of how much reagent you've delivered, you'll see that it doesn't matter as long as you take your reading from the same point. I like to use the very tip of the plunger because it is easiest to see. But I've had syringes (not from a Salifert kit) that had little black O-rings on them and that was even easier to see so I used that. __________________ David Current Tank: Undergoing reconstruction...

05/13/2015, 02:30 AM	#2
Tarawa Registered Member Join Date: Feb 2014 Posts: 245	the way your pic is showing it is the way I always do it

05/13/2015, 04:03 AM	#4
downbeach Registered Member Join Date: Nov 2006 Location: Smyrna, Delaware Posts: 3,767	Your picture is accurate, the space(air) that is between the top of the fluid and the bottom of the black part of the plunger is equal to the amount of fluid that is in the tip itself. You will also use the black part, (not the top of the fluid), to determine your reading, since that will indicate the amount of fluid it took to get the end point color, which includes the fluid that is in the tip.

05/13/2015, 07:37 AM	#7
Kaidman Registered Member Join Date: Mar 2015 Location: Evansville, IN Posts: 153	Funny, I just got my salifert kits last week and did the same test this weekend. I had the same question, it looked weird. The bubble ended up right around 0.8 for me also. Glad I wasn't doing something wrong! The test is still accurate as long as you start the black portion right at 1.0. You will have added the same amount of the reagent to the water if you have a bubble or not. The bubble takes up the same amount of space once you get the reaction to occur. It just messes with your brain...

05/14/2015, 11:33 AM	#10
One fish Registered Member. Join Date: Oct 2014 Location: Springfield Va Posts: 297	I really really appreciate the feedback. So my black spacer is in the correct starting point, got it. The big problem that I am having is that the starting line of the liquid changes every time I draw back. It is not consistent. I drew a total of three times and received three different results. The first time was 8.6. The second time I draw it is 8.2(as shown in the picture) and the last time is even on 9ml. Can anyone compare this to their own kit and tell me where theirs starts?

05/14/2015, 11:43 AM	#11
Sk8r RC Mod Join Date: Feb 2006 Location: Spokane WA Posts: 34,628 Blog Entries: 55	Push the plunger all the way to the bottom (point downward) when starting to draw fluid, then pull up (learning how to do this one-handed is a learning curve). Pull up until the bottom of the black hits the 0. Ignore the air space. That's allowed for by the originating lab's chart. To get a good view, set the vial on a white surface while dripping reagent in---this lets you see the reaction clearly: especially important if you have a colorblindness issue. You will note that as you approach a point of reaction, you will see a 'flash' of color that immediately goes away. This flash tells you you are approaching the reaction point. Another few drops will do it. In reactions like the alkalinity test that don't require an elaborate timed mixing procedure, you can speed the tests by watching for that flash as you rapidly add drops, and as you do see it, slow way down so that you don't miss the reaction point. You can use your log as a reference. If last week the reaction point was at the place on the chart that's 8.3, and you're pretty sure you're in that territory this week, you know that you will have quite a lot of the test where you can add VERY rapidly. As you get closer to 8.3 territory, you slow down drop by drop and catch your reaction point. I know, it's cheating. But it still gives a result. __________________ Sk8r Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low. Current Tank Info: 105g AquaVim wedge, yellow tang, sailfin blenny,royal gramma, ocellaris clown pair, yellow watchman, 100 microceriths, 25 tiny hermits, a 4" conch, 1" nassarius, recovering from 2 year hiatus with daily water change of 10%.