
What is the Redfield Ratio?
The Redfield Ratio is the recurring ratio of 106:16:1 of carbon to nitrogen to phosphorus (C:N:P) found in marine phytoplankton.
What’s the Redfield Ratio’s Practical Use?
In nature, corals feed on phytoplankton, even the corals who live in symbiosis with zooxanthellae. When they digest the phytoplankton, they get C, N and P in the Redfield Ratio or close to it. Corals then use the C, N and P they have consumed to build up their tissue.
To feed corals in an aquarium in a similar fashion, the easiest way to do it is to feed them a liquid nutritional supplements, like ATI Nutrition. Feeding them phytoplankton directly is difficult because farming phytoplankton is complex. Feeding it as a powder food will unnecessarily pollute the water, because most of it will not be consumed by the corals and instead will break down in the tank creating waste.
How To Maintain Proper Levels of Carbon, Nitrogen and Phosphorus
The basics are as follows:
- Dosing Carbon: Reduces both Nitrate and Phosphate when one of both of them is too high
- Dosing Nitrogen: Increases nitrate when it is too low
- Dosing Phosphorus: Increases phosphate when it is too low
Here’s how it all works:

For dosing calculations to determine the proper amounts of carbon, nitrogen and/or phosphorus (C:N:P) for the specific needs of your aquarium, please click here to visit our partners at ATI Aquaristik.
Pro Tip: A highly efficient protein skimmer is an absolute necessity to safely remove the extra bacteria that can accumulate in your aquarium when using ATI Nutrition or any other nutrient management program.
What is the Purpose of ATI Nutrition?
ATI Nutrition is designed to feed corals the correct ratio of C:N:P they crave, especially when nutrient levels in an aquarium are low. When used properly, the nutrient levels in the tank should not increase. If nutrient levels increase too much product is being used which can lead to nuisance algae growth, cyano-bacteria, diatoms or dinoflagellates.
What About Vodka Dosing?
Have you ever heard of people dosing vodka into their aquarium and wondered: what in the heck are they thinking? Vodka is an excellent source of carbon, however we do not recommend using it as a carbon source because overdosing can lead to catastrophic overgrowth of bacteria, consuming all the oxygen in the water column and killing everything in the tank.
What’s The Difference Between Carbon Dosing vs Dosing Active Carbon?
Carbon dosing and dosing active carbon sound similar, however they are two very different things. Active carbon, also known as activated carbon or charcoal, is used to absorb organics in the water. In contrast, carbon dosing is the process of adding carbon to the water to act as a food source for bacteria. These bacteria in turn consume nitrate and phosphate.
Interested in Trying Out Nutrient Management Yourself?
ATI Nutrition is our system-independent nutrient management program that is an effective, easy and natural method of nutrient control.
For more information, please visit: https://www.atinorthamerica.com/nutrition/