Macroalgae nutrition

[lone23]

First post.(Woot!) Hi everybody :)

Anywho, I have a question/idea. I'm currently running a 10g macroalgae tank though the only algae currently in there is Caulerpa Sertularoides and I have some Botryocladia and Codium on the way. However I have been noticing some die-off on my caulerpa and water tests revealed that even with heavy feeding of frozen foods, I have zero nitrates and phosphates.

My question is this: Would using water from an established fw tank as top-off water satisfy the need for nutrients (at least as far as nitrates and phosphates)? Is there anything that could go wrong with this that I should be aware of?

[Tom Barr]

Zero N and P.....most plants/algae would die............
You'd be fine from the FW, but keep the PO4 at or under 0.4ppm in marine tanks.
NO3 can be about 5-15ppm range without much issue

[JByer323]

Tom, would you be dosing KNO3 and KH2PO4 then for a marine seagrass/macro tank? Anything else?

[Tom Barr]

Tom, would you be dosing KNO3 and KH2PO4 then for a marine seagrass/macro tank? Anything else?

Same deal as FW(traces), Alk and Ca++ are very important more many macro algae also.

[JByer323]

Same deal as FW(traces), Alk and Ca++ are very important more many macro algae also.

I've never actually had a FW planted tank, about the time I was ready to get one my father got the saltwater bug, and we set up a reef instead, but I want the best of both worlds. I've been reading your stuff for a couple of years, I'm just trying to figure it out as far as a marine tank is concerned.

I plan to run a kalk reactor.