Mangroves and Magnesium

[Starfishhater]

I read in a thread that mangroves deplete magnesium. Is there any truth to this?

[Starfishhater]

Bueller?

[Plantbrain]

Not enough to be of any consequence in a marine tank with high levels of Mg......all plants use Mg, most obviously for Chl a in the pyrrole ring.

Without that metal, the ring is grey, not green.
There are a few other uses, but whole the trees do use it, there's plenty around and it's not likely to be limiting to anything. Algae and other marine plants use some also.

[Eel Freak]

That's correct. Red mangroves use Magnesium to create an ion-gradient which allows the mangroves to pump out salt. I don't think they use enough to create much of a depletion that would require supplementation.

[burnah]

if they use it for excretion, the only thing you have to do is wash the leaves with RO-water pouring into the tank - there it goes again...