I have been searching for the question, how much flow a coral need? When purchasing corals, the instructions usually state low, medium, or high flow but that does not tell me anything. I discovered a Youtube video by Vivid Aquariums entitled "Defining Low, Medium, and High Flow in a Reef Aquarium" and they suggested using the tank only volume of seawater. For example, if you have a 50-gallon tank, use the inter measurements for the calculation and when I did, it was around 45-gallons of seawater.
- Low flow usually around 10 to 15 times per hour
- Med flow usually around 15 to 17 times per hour
- High flow usually around 20+ times per hour
- Low 450 - 675 gph
- Med 675 - 765 gph
- High 900+ gph