Some of the most beautiful things in our reef tanks are not corals, but rather algae. Marine macro algae comes in a wide assortment of shapes and colors. Here you will find various types of macro algae that Tidal Gardens has been cultivating. These algae can be planted in the main display tank if there are no herbivores such as fox faces or tangs as well as in a refugium. In addition to providing aesthetics, decorative algae absorbs nitrate, phosphate, and heavy metals which are detrimental to the health of the reef..