Macroalgae is a wonderful organism to implement in your aquarium because it can help export nutrients and provide breeding grounds for copepods. One of the biggest and most discussed indicators of high nutrients is rapid algae growth. If you have a monstrous amount of hair algae or that yucky film algae, it is most likely due to a high amount of nitrates and phosphates. These nutrients are like food for the algae. As long as it has food, along with light, it will continue to grow. You could scrape the algae off the glass and scrub the rocks every day and it will still grow back. There are many solutions to this problem. You could use a protein skimmer, but even with a protein skimmer, you may still have a nutrient overload issue. Water changes are another thing you can do, although you should do water changes anyway. You could feed less or turn down the intensity of your lights. A combination of all these things is best, but what if you fought the algae with algae? Macroalgae is a large, plant-like form of algae. Another name for macroalgae is seaweed. Like the nuisance algae, macroalgae feeds off the nutrients in the water. As it absorbs the phosphates and nitrates from the water, the annoying algae will have less food, causing it to grow slower. Even if you do not have an algae problem, using macroalgae can be beneficial because it will prevent algae from becoming a problem. Macroalgae is mostly used in refugiums or the refugium section of a sump. These macroalgae can also act as a habitat for copepods in your refugium. The copepods will eat detritus the collects in the algae and reproduce. Tiny crustaceans such as copepods and rotifers love to live in macroalgae. Along with that, some macroalgae can be used for aesthetic purposes. Dragon’s Tongue algae, which is red with a branching pattern, looks particularly beautiful in a unique way. Sea Lettuce algae can be used to add a more natural look as well. Macroalgae is more than just algae. This plant-like algae will assist in removing nutrients, provide a place for copepods to breed, and it can add some natural depth to your display tank.