Magnesium help

[morgan175]

My tank is 110 with a 30 gallon sump. I have two korolla 1400 power heads and about 120 pounds of live rock and about 2 to 3 inch of sand. I have been using aquavitro salt for my water changes. I have a fox face and a green chrome for fish and about 50 snails and 4 hermits. Corals are frogspawn hammer blasto trumpet and a couple others I don't know. I can't keep zoas they just melt away.

Nitrates low can't read because seachem test kit
Calcium around 380 hannah
Alkalinity around 9.1 dkh
Mag around 800

I have slowly tried to raise mag with a fluval magnesium by adding 100ml a day but the mag has not raised at all. My question is does carbon (black diamond) remove mag or does the copersorb by seachem remove mag. I figured it would raise by at least a 100 by now but just sits at 800. Using Red Sea triton test. Do others really have succes with there DIY with Cvs I heard sulfates go up.

[disc1]

Is it really at 800? I'd verify that a couple of times over before I really reacted. That's unbelievably low.

Magnesium supplements are generally not very potent. I mean a lot of what's there isn't magnesium. Most of it, even in crystals, is water. So it sometimes takes a whole lot of magnesium supplement to barely even budge the mag number.

If mag is really that low, then you're right you don't want to raise it all the way with epsom salts (magnesium sulfate). You want to have a mix of that and magnesium chloride.

[Forgiven1973]

Maybe a faulty test kit? Compare with someone u might know or try another kit.

[bertoni]

Neither carbon nor Cuprisorb absorb magnesium. I agree that a second opinion on the test kit is key. What does freshly-mixed saltwater measure, and what brand of salt are you using?

[morgan175]

I will check new saltwater tomorrow. I use aquavitro by seachem. Will be going to io reef. Looking for someone that has one no luck yet. I thought salifert was a good test kit. What do you all use and salinity I forgot is 1.025

[bertoni]

The Salifert magnesium kit seemed to work well enough for me, but verified standards are expensive, so I was just checking consistency and general sanity.

[Psyops]

IF you are going to switch to the Instant Ocean brand, then just get the regular crystals. You don't have too much SPS so you might not need that extra calcium and alk numbers. Just a suggestion. As others have said, just test the Mg with another test kit or your LFS can try.

The two Salifert Mg test kits I have had always showed low numbers. I have not tried some of the others, but ELOS brand for Mg have shown consistent numbers. Hope this helps.

Alex

[morgan175]

Just ran test on fresh salt mix and I got 825. Pretty sure it has to be the test. Sorry to all it is a red sea magnesium test kit.

[krakenster]

its either the test kit or you are conducting the test wrongly.

[bertoni]

Or the salt mix has problems.