Macro algae is not just for looks or for helping to reduce nitrates. It is also an outstanding living natural food source for ALL your fish. Even your carnivorous fish need macro algae. They acquire it's nutrients from the many pods and shrimp in their diet. These eat macro algae and acquire the nutrients that it has to offer. So, when your Lionfish eats saltwater shrimp or your Mandarin chomps on some Pods, they are also benefiting from the nutrients provided by macro algae.