Red Sea MG test - cannot replicate

[Dank]

I've tried a dozen times to replicate the mg test. Both for tank water and newly mixed saltwater. I am all over the board.

I'd like to understand if I need to dose mg. But test results are so random, I wouldn't know where to start.

I follow the instructions to a T. Thoughts or tips?

 

[rtparty]

I've tried a dozen times to replicate the mg test. Both for tank water and newly mixed saltwater. I am all over the board.

I'd like to understand if I need to dose mg. But test results are so random, I wouldn't know where to start.

I follow the instructions to a T. Thoughts or tips?

What numbers are you getting? Is it a huge range?

 

[Dank]

Yes. All over the place. 1000k-1400

 

[cmcoker]

I like using a tuberculin syringe (1cc) to draw the test sample. 2ml is not very accurate in that 10cc syringe they provide, add an air bubble to that and who knows if your testing 2.0ml or 1.9ml. Doesn't sound like much but its a 5% difference in the sample size.

Also just to be sure, you are adding the first 5 reagent drops one at a time and mixing between each drop? Many people miss that

 

[Dank]

Yep. One at a time. I'll try using the 1 ml syringe for test sample.

 

[Ouscazz]

Mg can be a bit tricky to test, it's so easy to get it wrong.

I do it like this:

1. Rinse the glass container with RODI water.
2. Rinse the glass container with tank water.
3. Let the glass container dry completely. One single drop of tank water left in the container will ruin the test.
4. Rinse reagent fluid syringe with RODI water, blow and let it dry completely.
5. Add exactly 2 ml of tank water with a 1ml syringe to the glass container.
6. Slowly add about 70% of the expected amount of reagent fluid with the syringe.
7. Then start to add reagent drop wise stirring the test sample at least 2 seconds between drops.
8. Stop adding reagent fluid at the initial change from purple to a clear blue end color. The blue will only stay stable for a couple of seconds so pay close attention.
9. Read the used amount on the syringe and compare with the chart.

Remember, Mg tests generally have a resolution of +/- ~30ppm. Never react and take action after a single reading, look for trends over a week or two, or more.

 

[SPR1968]

Mg can be a bit tricky to test, it's so easy to get it wrong.

I do it like this:

1. Rinse the glass container with RODI water.
2. Rinse the glass container with tank water.
3. Let the glass container dry completely. One single drop of tank water left in the container will ruin the test.
4. Rinse reagent fluid syringe with RODI water, blow and let it dry completely.
5. Add exactly 2 ml of tank water with a 1ml syringe to the glass container.
6. Slowly add about 70% of the expected amount of reagent fluid with the syringe.
7. Then start to add reagent drop wise stirring the test sample at least 2 seconds between drops.
8. Stop adding reagent fluid at the initial change from purple to a clear blue end color. The blue will only stay stable for a couple of seconds so pay close attention.
9. Read the used amount on the syringe and compare with the chart.

Remember, Mg tests generally have a resolution of +/- ~30ppm. Never react and take action after a single reading, look for trends over a week or two, or more.

+1

The Mg test is very sensitive so don't react to any 'odd' readings until they are checked. I know from experience!

 

[Dank]

Mg can be a bit tricky to test, it's so easy to get it wrong.

I do it like this:

1. Rinse the glass container with RODI water.
2. Rinse the glass container with tank water.
3. Let the glass container dry completely. One single drop of tank water left in the container will ruin the test.
4. Rinse reagent fluid syringe with RODI water, blow and let it dry completely.
5. Add exactly 2 ml of tank water with a 1ml syringe to the glass container.
6. Slowly add about 70% of the expected amount of reagent fluid with the syringe.
7. Then start to add reagent drop wise stirring the test sample at least 2 seconds between drops.
8. Stop adding reagent fluid at the initial change from purple to a clear blue end color. The blue will only stay stable for a couple of seconds so pay close attention.
9. Read the used amount on the syringe and compare with the chart.

Remember, Mg tests generally have a resolution of +/- ~30ppm. Never react and take action after a single reading, look for trends over a week or two, or more.

Very helpful. Will give another go. Thanks.