Macro algae functions.

tyler1503 · Jan 30, 2015

Hello R2R!
I've read a few times, here and elsewhere, that macro algae can replenish certain things in the water column that are vital for coral health.
I understand how it reduces nasty things in the water column, but how does it add good things? I'm not exactly sure what, if anything it is supposed to replenish, it's just something I've read.
Thanks in advance!

Randy Holmes-Farley · Jan 30, 2015

I don't believe that macroalgae adds anything to the water that is needed for coral health.

It might release some organic matter, and that might end up as coral food directly or indirectly, but that is a very minor effect, if real. This released organics might be more of a negative effect than a positive one.

mtfish · Jan 30, 2015

I agree with Randy on this one. The macroalgae acts as a reservoir for nutrients. When it grows it removes nutrients from the water. If you harvest this algae then it is removed from the system. If it starts to die back then it releases the nutrients back into the system. I have lots of macro in my tank and use it as part of the filtration by removing it as it grows, sort of an in-tank algae turf scrubber.

jmarcink91 · Jan 30, 2015

The only thing I can think of that it might help "replenish" could be oxygen levels. Macro algae will consume some CO2 and give off oxygen in return. Other than that I agree with the above two statements.

Randy Holmes-Farley · Jan 30, 2015

Yes, it does add O2 during the day and consume CO2 during the night, which helps equalize the pH swing if it is lit at night in a refugium.

beaslbob · Jan 30, 2015

My take is that while the main thing is the ammonia/nitrate/co2 reductions, the macros themselves are food for fish and cleaner crews and provide an environment for pods as well. So I guess those would be good things the macros returns.
basically you recycle fish wastes into fish food and oxygen.

tyler1503 · Jan 30, 2015

Thanks everyone. It didn't make sense to me that macro algae would do much as to replenish anything. From what I've been reading, it seems some people believe macro could replenish trace elements or something :S

Randy Holmes-Farley · Jan 30, 2015

tyler1503 said:
Thanks everyone. It didn't make sense to me that macro algae would do much as to replenish anything. From what I've been reading, it seems some people believe macro could replenish trace elements or something :S

As noted, it would only deplete trace elements.

cope413 · Jan 30, 2015

It also provides a food source and hiding place for pods, so in that way it "adds" that to the water which can be very helpful to both coral and fish.