Magnesium

[BradMugs]

HI, be gentle I'm new to this stuff. I'm looking at going more towards SPS or LPS than the softies I've got outgrowing my tank right now so I though I'd at least meaure my Mg. Picked up the Salifert kit and did the test - my LFS recommended it and also gave me one on one instructions on how to use it (just what the instructions said but they made it very clear).

So, I ran my test - 990 ppm way below the recommended. I do a 10% water change on Monday's and I ran this test on Saturday so more than half way through the week. I will re-test after my next water change to see what it looks like then but either its always low or I'm using it up pretty fast with the little bit I've got in there now.

I'm looking for recommendations and how to apply. I've got Lime in my top off water - can I add the Mg to that or should I add separately?

Thanks

[ruggirello2]

add it seperatly. I use kent's tech m. You can raise it up to 1250-1350 in a matter of a couple days, then start testing weekly to see how much it dropped. More importantly you need to check alk anc ca.

[Randy Holmes-Farley]

The perennial question in such a situation is whether the test result is accurate or not.

What salt are you using? What salinity?

Ever measure the new salt water itself?

[BradMugs]

ruggirello

I check a bunch of things - first check for Ma. What is ANC?

Randy,
Reef Crystals - 1.025 is the goal when mixing. Usually +-.002 Normally +-.001.

I'll check the mix when I make some up.

[bertoni]

I think he meant alkalinity and calcium.

I wouldn't do any dosing until the fresh saltwater has been tested, personally. 990 ppm is low enough that I worry about a serious testing problem.

[ruprecht]

Originally Posted by BradMugs

ruggirello

I check a bunch of things - first check for Ma. What is ANC?

Randy,
Reef Crystals - 1.025 is the goal when mixing. Usually +-.002 Normally +-.001.

I'll check the mix when I make some up.

Using a calibrated refractometer? Are you using a bucket of salt? I have heard that salts can (very rarely) stratify during transport.

Could unsubstantiated claims of EDTA in Instant Ocean products keep magnesium from being accurately measured (if they were in fact true) ?

[Randy Holmes-Farley]

No, there is not going to be enough metal chelator in Reef Crystals to impact magnesium measurement.

[BradMugs]

Yes Refractometer

Box of bagged salt

EDTA?

[bertoni]

EDTA is a metal chelator, that is, it combines with a metal. They can neutralize (at least temporarily) copper and other metals. The question was whether the salt product could contain enough chelators to reduce the magnesium level.