Hi Tom and folks!

I was wondering if the copper (Cu) in TMG (now Plant Nutrition) could be an issue in marine tanks? Is it toxic in those ammounts that is in TMG? On my bottle it says Cu 0.006% and Fe 0,07 (W/W%).

Do macroalgae need Cu - as do freshwater plants - or not?

Or do macros just need iron (Fe) and I would be better off with Flourish Iron (even with it being worse chelated)?

I have a 30 liters tank and dose about 1 ml of TMG twice a week. So the next question is - do I get enough Fe with such dose without overdosing Cu, or should I dose more and not worry about coppers toxicity?


My tank inhabitants are a lot of macroalgae, some mushrooms, a single LPS-coral (Lobophyton), one turbo snail and two small ocelaris. Light about 1 w/liter.

Nobody has an idea?

I doubt these levels are problematic.
They are pretty low.
You can use a copper test and see for yourself.

Regards,
Tom Barr

Allright, I see, thank You Tom, but do macroalgae need copper (for example for fotosynthesis)?

Yes!!

Regards,
Tom Barr

Danke, Tom! One can say that macros can "purify" water from heavy metals, right?(which could be a good thing for other sessile invertebrates)

Well, healthy actively growing one can and do, they also release metals if they decay..........

Inverts are very sensitive to metals.

Regards,
Tom Barr