It has been long held that silica in reef tanks is bad, very, very bad. We avoid beach and play sand like it’s poison because it is believed that silica will cause an undesirable diatom bloom: brown glass, brown gook on rock and substrates, and unhappy reefkeepers. But what if we could control this system and use it to our advantage…say, to increase nutrient export? Let’s take a look at some old data, some new data, and a controversial hypothesis: that dosing silica may increase nutrient export efficiency.