Magnesium Test Kit

[starsbravo]

Can I buy directly from you Jesse? There are no vendors in my area that sell your products. Thanks

Josh

[elosusa]

yeah no problem just give me a call. I will clean out my pm box, sorry.

[disaster999]

i want to get the magnesium test kit too. how much is it if i by directly from you jesse?

[elosusa]

31.99. Marine Depot will have them available this weekend, I believe. You can also try phishybusiness.com and barrierreefaquariums.com.

[Canarygirl]

I'm having trouble using the Mg test kit.

I'm wondering, is there supposed to be a color card included to show how deep a blue color is the expected end point? The instructions just say to count drops "until solution turns blue" but the first blue that happens is a light pastel blue and after adding several more drops this color does not change. Is there something missing from my test kit (color card)? It's hard to use the way it is now....

Thanks

[elosusa]

Hey Canarygirl.
There is no color card to the Mg kit. Is the blue a light blue or a blue with a touch of purple?
I have tested a bunch of different salt mixes and sea water from different locations and you will get different shades of blue from most all of them but the important part is getting the same blue after 30 seconds of shaking it after the last drop of reagent C. If it is pinkish or purplish blue, this is not your end point. When I test batches against blind lab samples after they enter the US, there are few things that are important on the Mg kit.
1a. Make sure to shake all the liquid reagents before you start the test.
1b. On the first step, adding the 3ml test water for normal resolution and then adding 9 drops of reagent A, make sure to shake the vial for the full 30 seconds before adding reagent B as the instructions indicate . This is a key step in getting an accurate number.
2. After you have reached a blue color, make note of that color, and continue to shake the vial for 30 seconds. If after the 30 seconds you have the same color blue, this is your reading. If it lightens or goes to a "pastel blue" then add one more drop of reagent C and repeat.
I hope that helps and let me know if you have any other questions. BTW, I will pm you back, this post just reminded me;)

[Canarygirl]

Thankyou, Jesse.

I will repeat the test tonight because I know I didn't perform it exactly that way; I didn't shake the reagent for 30 seconds, for one thing.

THe only blue color I reached was a pastel blue and it stayed that way even after adding more reagent. Hopefully I'll get a different result after doing a retest.

I will repost after doing that. :)

[lancer99]

I am still confused....

<a href=showthread.php?s=&postid=11539232#post11539232 target=_blank>Originally posted</a> by elosusa

1a. Make sure to shake all the liquid reagents before you start the test.
1b. On the first step, adding the 3ml test water for normal resolution and then adding 9 drops of reagent A, make sure to shake the vial for the full 30 seconds before adding reagent B as the instructions indicate . This is a key step in getting an accurate number.
2. After you have reached a blue color, make note of that color, and continue to shake the vial for 30 seconds. If after the 30 seconds you have the same color blue, this is your reading. If it lightens or goes to a "pastel blue" then add one more drop of reagent C and repeat.

Do I have to shake the vial for 30 seconds after adding each drop of reagent C, or just after getting the blue?

BTW, the instructions mention nothing about shaking for 30 seconds after adding reagent A (they say "a few seconds"). Only the quick reference card mentions it.

Thanks,
-Robert

[elosusa]

Shake a few seconds between drops of C and when the color changes then shake for a full 30 seconds to be sure the color remains the same.

After adding the reagent A you should shake for a full 30 seconds before adding regent b. This step precipitates the Calcium in the solution, which will cause interference in testing for Mg.
Thanks I will note this for the printer on the written instructions and it is good to note that the reference cards are always going to be more up to date as we have these redone every few months with the colorimetric kits cards as they need to be checked to make sure color is correct against current batch of kits. Hope that helps and let me know if you have any other questions.

[lancer99]

Thanks, I appreciate your reply. I thought that was the case, but wanted to check, because I'm getting results of 16 drops (checked three times) in one of my tanks and 17 drops with Reef Crystals, which seems way too high. I'm using the air gap/water line to 5 mls/plunge to 2 mls, to be sure I'm getting 3 mls of sample water.

Since this isn't a 12/09 expiry date kit (it's 2/10), those readings seem very high. I haven't added any Mg supplements. Could my readings really be that high, or is it possible the test kit is defective?

Thanks again,
-Robert

[elosusa]

I believe I have heard this recently with reef crystals? I know I had a few customers ask about the same thing and it turned out it was the saltwater. As with all of these things of course something can happen with your kit but the batch tested out both in Italy and with the US lab we use, so I suspect the kit is reading correctly. Is there a chance you can test another persons water who is using a different salt mix? If you still believe it is the kit send me and email with your address. Thanks.

[lancer99]

I'll buy a different salt at my local LFS tomorrow, mix up a batch, and test on Friday. Hopefully they have Seachem, as I've heard rumors that it's low in magnesium.

I appreciate your responsiveness....that is great customer support.

Cheers,
-R

[coseal]

should put together a video for each kit!

[lancer99]

<a href=showthread.php?s=&postid=12072682#post12072682 target=_blank>Originally posted</a> by elosusa
I believe I have heard this recently with reef crystals? I know I had a few customers ask about the same thing and it turned out it was the saltwater.
I finally found some time to do this, with Tropic Marin (regular, not pro), at 35 ppt.

1100!!!

So it is indeed Reef Crystals that is the problem.

Well at least I don't have to worry about supplementing Mg for a while :)

-R