Is this just trading one evil for one that's more tolerable?

[Marquiseo]

I understand that "nuisance" algae sucks in all available nutrients from corals and that we use macro algae such as chaetomorpha to inhibit the growth of the "nuisance" algae by absorbing the available nutrients in the water column. Isn't the macro algae doing the same exact thing the "nuisance" algae was doing? The only difference I can see is that it is in a "controlled" environment depending on the macro algae species. In the end, the same amount of nutrients is being taken away from the corals.

I am I wrong somewhere?

 

[Randy Holmes-Farley Verified Community Expert]

I'm not sure that algae of any kind suck nutrients out of corals. Reducing nitrate and phosphate in the water is generally considered a benefit, whatever does it.

We do not like nuisance algae because it looks bad and can grow over desirable organisms.

Macroalgae can usually be confined to a refugium, so it isn't a problem in the main tank.

 

[Marquiseo]

I'm not sure that algae of any kind suck nutrients out of corals. I think you read too much into what I wrote so I will clarify. By that I meant, all the available nutrients is used by the algae before the corals can use it. I used "suck" because as the algae grows and spreads, there will be a significant decrease in available nutrients for corals.


Reducing nitrate and phosphate in the water is generally considered a benefit, whatever does it.
I wasn't stating it was a bad thing. I was implying that using "fire to fight fire" is pretty much trading one thing for another.

We do not like nuisance algae because it looks bad and can grow over desirable organisms.
That is understood but the commonly used macro algaes such as Chaetomorpha and Caulerpa Algae can do the same if introduced accidentally or intentionally into the main display.

Macroalgae can usually be confined to a refugium, so it isn't a problem in the main tank. Not as an intent to go against what your are saying but there have been several instances of Caulerpa Algae going sexual in home aquariums which doesn't just remain in the refugium area or several incidents of macro algae pieces being sucked into the main display via the return pump.

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^

 

[RMS18]

We use these "controlled algae" to reduce the levels which support the growth of nuisance algae, that can grow on our corals, rocks and sand bed. Yes we are fighting fire with fire but we have control over the second fire to reduce the first fire. There is always a chance of getting burned when playing with fire... these analogies working for ya lol. For some people like myself who have nuisance algae i am willing to try cheato in my fuge to help me fight this battle.

 

[Daniel@R2R Verified Admin]

As stated above, the nutrients in the water are detrimental to corals if not controlled through an export strategy (i.e. refugium, carbon dosing, etc.), so I don't think the idea is to remove nutrients available to corals for their needs since this presupposes that corals are in need of the nutrients that are being removed. An analogy that might help is to imagine our own food needs, but then imagine if food became more and more plentiful to the point that we were buried in it. Or perhaps imagine our own need for oxygen, but then imagine what would happen if oxygen levels in our atmosphere were increased exponentially...eventually to a point that it becomes harmful to us. Too much of a good thing is a bad thing, and too many nutrients in a tank is bad for corals.

So...the question then becomes (since we have established the need to remove them), is a refugium an adequate or good way to do this? I think that citing all of the successful aquarists who use refugiums proves their efficacy. You mention calerpa going sexual and spreading to a display, and you are correct that this does sometimes happen with certain types of calerpa. This is a big reason most of us use chaeto which is not known to do this.

HTH