Mg ?????

[andrewbram]

I just used a salifert Mg test and I am really confused. My Mg is either 900 or 1200. The reason I am so confused is the directions say to add the pink tip then draw from bottle three when I do this it has a .1ml air bubble. at the end of the test My reading is between .2 and .4 . I drew air at end of test so I can reed the two liquid lines in syringe if I dont draw the air it says.2 this is why I am confused. please help because I can not get my alk and ca to raise and I am sure its my mag being low but dont want to raise it to much or to fast unless I am supposed to.

[Randy Holmes-Farley]

You read the reading from the end of the syringe barrel, and ignore the air that needs to be in the syringe. :)

[andrewbram]

Ok I will try it one more time then post my results with picture.

[Randy Holmes-Farley]

Sounds good.
The CEO of Salifert is currently online here if you have issues that need his assistance. :D

[andrewbram]

This was at start it was .2 ml air bubblehttp://i1067.photobucket.com/albums/u424/andrew_bram/DSCN0759.jpg
http://i1067.photobucket.com/albums/u424/andrew_bram/DSCN0767.jpg
The second picture I placed the nail where the air bubble is. However there is still .2ml of liquid left when I draw back on syringe. I work in medical feild and this just doesnt seem right lol. Thank you Randy for answering my questions. So if the pick with nail is correct reading I am at 1350 for Mg. Which brings up why wont my alk and ca come up. I started at 7ml up to 12ml, 16ml,20,now at 25ml of two part. I am a 2 inch green slimer frag and a 2 inch birdnest alone with 2 3-4 inch lps and some softies. Its a 75g with 29g fuge. My alk wont raise above 6-7. I also have a ton of coraline it covers everything.

[disc1]

The point to using that syringe is to measure how much you pushed out of it. The easiest way is to use the black tip of the plunger to mark the position. You are reading the difference between where it is when you start vs where it is when you finish, so the actual starting position or the amount that is actually in the syringe is irrelevant. The air between the liquid and the piston represents the volume of the tip and you should leave it there or you end up delivering more than you can measure.

For example, if I pull the piston up until the black part is at 1.00 and then at the end of the titration the black tip is at 0.20 I used 0.8ml of titrant, regardless of how much air there was or anything else. Only concerned with how far you moved the piston.

If you look at the directions, the chart has you reading the final position of the piston, but if you think about it for a minute, you can see where they've done the subtraction for you. You could just as easily make that chart read using the amount actually delivered. In that case, you could start at (for the same as the above example) 0.90 and end at 0.10 and you still pushed in the same 0.8mL. I wouldn't do that since it creates math, but only using it to illustrate the point that it is the difference and not the absolute volume in the syringe that matters.

[disc1]

This was at start it was .2 ml air bubblehttp://i1067.photobucket.com/albums/u424/andrew_bram/DSCN0759.jpg
http://i1067.photobucket.com/albums/u424/andrew_bram/DSCN0767.jpg
The second picture I placed the nail where the air bubble is. However there is still .2ml of liquid left when I draw back on syringe. I work in medical feild and this just doesnt seem right lol. Thank you Randy for answering my questions. So if the pick with nail is correct reading I am at 1350 for Mg. Which brings up why wont my alk and ca come up. I started at 7ml up to 12ml, 16ml,20,now at 25ml of two part. I am a 2 inch green slimer frag and a 2 inch birdnest alone with 2 3-4 inch lps and some softies. Its a 75g with 29g fuge. My alk wont raise above 6-7. I also have a ton of coraline it covers everything.


Please forget EVERYTHING you have ever learned about using a syringe in the medical field. This is very different from giving an injection. We are using the syringe backwards of what you are thinking.

[disc1]

So from what I see in the picture, you have the piston at 1.0 to start and 0.2 to end, so you used 0.8ml of titrant. On your salifert instructions, the answer is on the line with 0.20 as the final position.

[andrewbram]

Ok that makes sense disc1. So my reading would be .2mlbased off where my plunger started and ended so about 1200ppm. So would being down that far from 1350 cause my alk and ca not to raise.

[Randy Holmes-Farley]

The second picture I placed the nail where the air bubble is. However there is still .2ml of liquid left when I draw back on syringe. I work in medical feild and this just doesnt seem right lol. .


It definitely wouldn't be right if you were to inject air into someone. That's why they take the steps to blow out the air. In our case, you dispense in a vertical position and the air just stays inside, and if some got out, not a big deal. :)

[andrewbram]

So if I am right on my Mg level then I need to use 403g of reef advantage magnesium. That is based on 85 gallons of water to raise it from 1200 to 1300. That really seems like a lot to add at once. thoughts on this.

[Randy Holmes-Farley]

It always seems like a lot to folks, but bear in mind that 85 gallons of water has nearly a pound of magnesium in it, and that most solid magnesium supplements are only about 10% magnesium ion by weight. :)

[andrewbram]

Thanks Randy and David for all your help. Can I add it all at once or should I drip it in?

[Randy Holmes-Farley]

I'd split that dose in half, the second one 24 h later. :)

[andrewbram]

ok will do. Thank you very much.

[Randy Holmes-Farley]

:thumbsup:

Happy Reefing. :)

[T Diddy]

great info here. :beer:

[andrewbram]

Well I am dripping in the first half right now. Then I am going to retest in the morning before I add the second half because I figure it can not hurt to retest.