How Effective is Macroalgae

[chrispyness]

Hi everyone,

I’m planning my first saltwater tank. I have a 60g cube I’ll be using as a display tank with a sump.

I’ve been keeping freshwater for about two years at this point. I’ve always kept planted tanks to help keep nitrates down and have had massive success letting nature do its thing with occasional water changes.

How much can I transfer this experience to saltwater with macroalgae? Freshwater plants like pothos, Java fern and many others do great at purifying the water. I know macroalgae will do this to an extent but I don’t know the effectiveness of it.

Is it best to keep it in a refugium or in the tank?

 

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It depends on what you want your tank to look like. Having both experience with freshwater and saltwater I will say that macroalgae does have to be trimmed more often then freshwater plants. It does a great job in removing excess nitrates and phosphates in the tank, and while this does cut back on your need to do water changes, you do have to dose your tank for calcium, alkalinity, and magnesium as they will suck those up as well.
Keeping it in a refugium makes it a little bit more manageable but it also limits the growing area. If you wanted to put it in your display be wary of it growing over corals and covering them. If you wanted to do just a macroalgae tank I recommend something like Dragon's breath as it's very pretty to look at and easy to remove.

 

[Subsea]

Hi everyone,

I’m planning my first saltwater tank. I have a 60g cube I’ll be using as a display tank with a sump.

I’ve been keeping freshwater for about two years at this point. I’ve always kept planted tanks to help keep nitrates down and have had massive success letting nature do its thing with occasional water changes.

How much can I transfer this experience to saltwater with macroalgae? Freshwater plants like pothos, Java fern and many others do great at purifying the water. I know macroalgae will do this to an extent but I don’t know the effectiveness of it.

Is it best to keep it in a refugium or in the tank?

I like macro algae in my display. Contrasting red (Bortacladia, Gracilaria Hayi) and green (Caulerpa Paspoidies)

 

[Piotrek]

It terms of trimming I recently started an experiment by chance. I purchased 3 fish: foxface, scopas and c. heraldi. The team already present in the display tank didn't like the addition, so I placed the fish in my display refugium. The eat macro like crazy. I'm still trying to *****, if the macro grows quicker then being eaten.
But the whole thing got me thinking, if it would be possible to run a big display refugium that could be introduced to some fish once enough macro exists, and if you could get away without feeding the fish at all.
I'm planning to gather data for a few months on the setup I have and starting a thread on this.

 

[Subsea]

“you could get away without feeding the fish at all.
I'm planning to gather data for a few months on the setup I have and starting a thread on this”

@Piotrek
In the long run, I don’t see this working. Fish need more than plant protein.

 

[Piotrek]

“you could get away without feeding the fish at all.
I'm planning to gather data for a few months on the setup I have and starting a thread on this”

@Piotrek
In the long run, I don’t see this working. Fish need more than plant protein.

Could you elaborate a bit, why this would not work? You do need to add some stuff to account for what is removed from the tank. Either by the skimmer, evaporation etc. So maybe feeding once a week or even less would do?
I can't at the moment check out the scenario, as I have clown fish and fridmani in my refugium that require feeding anyway.

 

[Gumbies R Us]

@vlangel

 

[Subsea]

Could you elaborate a bit, why this would not work? You do need to add some stuff to account for what is removed from the tank. Either by the skimmer, evaporation etc. So maybe feeding once a week or even less would do?
I can't at the moment check out the scenario, as I have clown fish and fridmani in my refugium that require feeding anyway.

I am not an expert on fish dietary needs. I grow macroalgae in mixed garden display tanks. To do this , I removed tangs & rabbits. Fish poop provide nutrients for seaweed and fish graze on biofilm that cover seaweed surfaces.

I don’t see the advantage of forcing fish to survive on one food source. Just my experience after 55 years of reefing.

Seaweed will require dosing of nutrients which is a seperate process that involves monitoring & testing. If that’s your thing, then go for it.