Macroalgae for Nutrient Control

Reef By Steele

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Back when I started my first Saltwater aquarium in 1991, I had no clue and very little information. I had done freshwater for a long time, but never a planted tank. When I started my first reef, I got some feather Caulerpa and loved how it added extra color and motion to my tank, little did I know that it would thrive and take over the tank nearly choking out my corals and covering all of my rock. I spent a lot of time pruning (ripping out) bunches of it to keep it in check. Later I got a trio of yellow tangs, and they really loved it. Within a week they had decimated the Caulerpa leaving nothing behind. Refugiums were just coming into popularity but I didn't understand them.

sm Ogo Coarse.png

Now 34 years later, while still having no clue, I have learned so much and have a much better understanding of how everything we can add to our tanks works together. While macroalgae can add color, movement and structure to our aquariums, it also has a utilitarian purpose as well. Nutrient export is a wonderful byproduct of the introduction of macroalgae into an aquarium. This benefit can be achieved whether it is added to the DT or placed in a refugium with a sufficient light source and flow.

sm Chaetomorpha Clean.png

One of the cool features of macroalgae is that every saltwater tank can benefit from it. While protein skimmers are such a great piece of equipment and really help with water quality, not everyone can utilize one as many state that hang-on units just don't perform to the level that in sump units work. That being said, macroalgae can be used in any tank from Nanno to Monster, AIO to fully plumbed DT with fuge. Even tanks with herbivores such as tangs can have and sustain macros, even in the DT, with proper selection. How is this possible, there are certain species that just don't hold the same appeal to the tangs as my Caulerpa did back in that first reef. Hayi Gracilaria (Pom Pom) is one such option. While they may initially pick at it, most times they leave it alone.

sm Pom Pom (1).png

In the DT there are many choices that can be both utilitarian and visually appealing. The Pom Pom mentioned previously makes cool roundish red balls. Our thick Ogo Gracilaria is another red option that grows at a reasonable rate, while being a branching variety. This makes a great home for seahorses also. Caulerpa Racemosa grows as green grape like clumps and can be very beautiful as well. Caution should be exercised with this as like my feather Caulerpa it can grow aggressively and overwhelm your tank without harvest.

sm Caulerpa Racemosa.png

In the refugium, every variety listed above does well also. Some reasonable flow and either a specific refugium light or many choose to just add a generic grow light and the addition of a starter macroalgae. Any of the macros we offer are great selections for a refugium and they are fast growing and hardy varieties. Cheatomorpha is by far the most widely recognized and frequently used variety. While fast growing and fairly easy to maintain, its wiry appearance and tendency to intertwine in rocks and other structure makes it less desirable in a DT but awesome in the fuge. We recently came a cross wild Chaetomorpha, which is cool as it has muscles and other life in it. Since it is ocean harvested we have isolated it in a fishless system for 6 weeks prior to adding to the site. While all three Gracilaria we have in stock are fast growing and excellent choices, I find the fine Ogo to grow the fastest, making it a great choice.

sm Ogo Fine.png

So how does macroalgae remove nutrients from the tank. All of these varieties use nutrients and photosynthesis for growth. What I didn't understand at first, is that while it consumes nutrients it doesn't remove them. In the event that the macroalgae were to die, the nutrients would be returned to the tank as it decays. For this reason, we must harvest a portion of the macroalgae routinely to fully remove the nutrients from our system. Pulling it out and disposing of it is the general method, but there are other options as well. For aquarists with herbivores, you also gain a free and sustainable food source for those fish. Rabbitfish and tangs love getting a supply of fresh algae for dinner. While this does return some nutrients back into the system as the fish digest and expel, this addition is not higher than feeding them nori or other algae based foods, and considerably less than algae pellets and wafers that may not all be consumed. So harvesting and feeding a portion of the harvest will still net you positive results along with happy fish.

sm Dragons Breath.png

As always, here at www.reefbysteele.com we are dedicated to our customers and fellow reefers and are more than happy to answer any questions you may have.

Happy reefing!
 

The Nautilus

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So if macro algae releases the nutrients back into the system when it dies, does that mean it can kill the tank through a spike in nitrates and phosphates? I would love to keep some in my display tank but there doesn't seem to be a lot of information out there? I'll personally be on the lookout for an algae that is slow growing so won't need cut back more than once a month if possible? More than anything I'm worried about a huge spike in nutrients so suddenly if it dies off but I guess this can be avoided if kept in small enough quantities, whatever that might be..
 
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Reef By Steele

Reef By Steele

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So if macro algae releases the nutrients back into the system when it dies, does that mean it can kill the tank through a spike in nitrates and phosphates? I would love to keep some in my display tank but there doesn't seem to be a lot of information out there? I'll personally be on the lookout for an algae that is slow growing so won't need cut back more than once a month if possible? More than anything I'm worried about a huge spike in nutrients so suddenly if it dies off but I guess this can be avoided if kept in small enough quantities, whatever that might be..
As with about everything in our tanks, a serious die off can have serious consequences. However micro die off, should not create a tank killing spike and the excess nitrates and phosphates would be removed with a medium to large water change. I haven’t ever had a rapid loss of macros in one of our tanks, would expect it to be something slower and noticeable. If it starts to wither, harvesting the affected portion would be advised. And a look at water parameters to determine cause (nitrates and phosphates should too low to sustain growth). Slower growing macros would be better in DT if you are running good nutrient numbers, faster growing if you are wanting to use it as an export method and harvest as it grows to export the nutrients.
 

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sm Atomic Broccoli.png

Back when I started my first Saltwater aquarium in 1991, I had no clue and very little information. I had done freshwater for a long time, but never a planted tank. When I started my first reef, I got some feather Caulerpa and loved how it added extra color and motion to my tank, little did I know that it would thrive and take over the tank nearly choking out my corals and covering all of my rock. I spent a lot of time pruning (ripping out) bunches of it to keep it in check. Later I got a trio of yellow tangs, and they really loved it. Within a week they had decimated the Caulerpa leaving nothing behind. Refugiums were just coming into popularity but I didn't understand them.

sm Ogo Coarse.png

Now 34 years later, while still having no clue, I have learned so much and have a much better understanding of how everything we can add to our tanks works together. While macroalgae can add color, movement and structure to our aquariums, it also has a utilitarian purpose as well. Nutrient export is a wonderful byproduct of the introduction of macroalgae into an aquarium. This benefit can be achieved whether it is added to the DT or placed in a refugium with a sufficient light source and flow.

sm Chaetomorpha Clean.png

One of the cool features of macroalgae is that every saltwater tank can benefit from it. While protein skimmers are such a great piece of equipment and really help with water quality, not everyone can utilize one as many state that hang-on units just don't perform to the level that in sump units work. That being said, macroalgae can be used in any tank from Nanno to Monster, AIO to fully plumbed DT with fuge. Even tanks with herbivores such as tangs can have and sustain macros, even in the DT, with proper selection. How is this possible, there are certain species that just don't hold the same appeal to the tangs as my Caulerpa did back in that first reef. Hayi Gracilaria (Pom Pom) is one such option. While they may initially pick at it, most times they leave it alone.

sm Pom Pom (1).png

In the DT there are many choices that can be both utilitarian and visually appealing. The Pom Pom mentioned previously makes cool roundish red balls. Our thick Ogo Gracilaria is another red option that grows at a reasonable rate, while being a branching variety. This makes a great home for seahorses also. Caulerpa Racemosa grows as green grape like clumps and can be very beautiful as well. Caution should be exercised with this as like my feather Caulerpa it can grow aggressively and overwhelm your tank without harvest.

sm Caulerpa Racemosa.png

In the refugium, every variety listed above does well also. Some reasonable flow and either a specific refugium light or many choose to just add a generic grow light and the addition of a starter macroalgae. Any of the macros we offer are great selections for a refugium and they are fast growing and hardy varieties. Cheatomorpha is by far the most widely recognized and frequently used variety. While fast growing and fairly easy to maintain, its wiry appearance and tendency to intertwine in rocks and other structure makes it less desirable in a DT but awesome in the fuge. We recently came a cross wild Chaetomorpha, which is cool as it has muscles and other life in it. Since it is ocean harvested we have isolated it in a fishless system for 6 weeks prior to adding to the site. While all three Gracilaria we have in stock are fast growing and excellent choices, I find the fine Ogo to grow the fastest, making it a great choice.

sm Ogo Fine.png

So how does macroalgae remove nutrients from the tank. All of these varieties use nutrients and photosynthesis for growth. What I didn't understand at first, is that while it consumes nutrients it doesn't remove them. In the event that the macroalgae were to die, the nutrients would be returned to the tank as it decays. For this reason, we must harvest a portion of the macroalgae routinely to fully remove the nutrients from our system. Pulling it out and disposing of it is the general method, but there are other options as well. For aquarists with herbivores, you also gain a free and sustainable food source for those fish. Rabbitfish and tangs love getting a supply of fresh algae for dinner. While this does return some nutrients back into the system as the fish digest and expel, this addition is not higher than feeding them nori or other algae based foods, and considerably less than algae pellets and wafers that may not all be consumed. So harvesting and feeding a portion of the harvest will still net you positive results along with happy fish.

sm Dragons Breath.png

As always, here at www.reefbysteele.com we are dedicated to our customers and fellow reefers and are more than happy to answer any questions you may have.

Happy reefing!
Enjoyed your write up. And will visit your website more often.
 

vlangel

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I enjoy keeping macroalgae in my sumpless display tank. Codium is nice in a display tank for a green option plus it does not get consumed by my Kole tang or Foxface. I also have cheato in behind my rockwork in the back where the flow is a little slower. And of course I have pom pom. I regularly buy ulva from our lfs since the herbivore fish enjoy it and they can graze on it very naturally.
 

Reeferbadness

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I have 2 x 200g tanks both with refugiums. I use mostly chaeto - and find that it does a good job on nutrient export. I take out about a softball size every 2 weeks. One thing i did notice is that it also sucks out a lot of nitrates. I have to compensate for this by dosing NeoPhos - around 6ml per day per tank. Phos is pretty stable but i still use some Rowa Phos to help keep it around .08

I did have a couple of outbreaks of bryopsis - which can quickly take over the tank and had to use Flux Rx. When doing this, i just took out all chaeto and then once treatment was completed, add back chaeto and all good.
 

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