There is a lot of confusion as to which media and methods work best for which situations or aquarium needs. Due to the nature of the name, “carbon dosing” is often misunderstood. When someone refers to carbon dosing this is not the act of using activated carbon, or charcoal but rather adding the raw element C – Carbon to your reef.
But why does my reef need the element C? It’s generally in short supply in an aquarium and because every living creature needs it, providing it can be beneficial.
What is Carbon Dosing and what are the pros and cons of using it?
The primary reason users dose carbon is to assist in controlling the nutrient levels in an aquarium. An aquarium is constantly producing organic waste in the form fish food, fish poop, dying organisms and other sources. As this waste breaks down it turns primarily into phosphates and nitrates which can lead to the proliferation of nuisance algae in an aquarium.
So how does carbon help? Carbon is a food source for beneficial bacteria in the tank. Adding carbon causes these bacteria to multiply and these bacteria in turn consume the excess nitrates and phosphates. The benefit is cleaner and healthier water for your fish and corals.
Pros of Carbon Dosing:
- Effectively removes excess nutrients in the tank, mainly phosphate and nitrate
- Low cost
- Ease of use
- No Additional Equipment Needed
Cons of Carbon Dosing:
- Must be started slowly
- Potential for overdose
- Can completely strip the tank of all nitrate & phosphate (Low levels of nitrate and phosphate are needed for ideal coral health.)
- Requires the use of a protein skimmer
- Most effective with equipment such as a dosing pump or media reactor
Find more details on Carbon Dosing here!
What are Bio-pellets and what are the pros and cons of using it?
One of the most common methods of carbon dosing are bio-pellets. Bio-pellets are simply biodegradable plastic beads made from fossil fuels. Fossil fuels are made primarily of carbon. The result is bacteria consume the pellets and proliferate while doing so. As the bacteria grow and reproduce they consume the nutrients polluting your aquarium.
Pros of Bio-pellets:
- Set it and forget it – requires very little maintenance
- Effectively removes excess nutrients in the tank, mainly phosphate and nitrate
- Lower risk of overdose compared to other forms of carbon dosing
Cons of Bio-pellets:
- Fairly costly to setup – A media reactor and protein skimmer are required
- Very little control on actual operation
- Consumes other trace elements stealing them from coral
- Can completely strip the tank of all nitrate & phosphate (Low levels of nitrate and phosphate are needed for ideal coral health.)
What is GFO and what are the pros and cons of using it?
GFO filter media is used in reef aquariums for removing phosphates, silicates and other chemicals from the water. Chemicals are attracted to the surface of the GFO by the process of adsorption whereby they are safely and effectively removed from the water. Even as the media is exhausted or used up it will not release the adsorbed chemicals back into the water column.
Pros of GFO
- Safely removes phosphates, silicates and other chemicals
- Inexpensive
- Readily available
Cons of GFO
- Removes trace elements
Remedy: Routine water changes or dosing of trace elements
- Can reduce alkalinity / pH
Remedy: Gently tumble media in a reactor or turn media in filter media bag to prevent it from clumping together.
- GFO dust is damaging to fish and coral
Remedy: Carefully rinse prior to use
- Removing phosphate too quickly
Remedy: Start with small amounts of GFO
Find more details on GFO here!
So should I run GFO or dose carbon? The simple answer is usually both! In most systems, the nitrates will be consumed before the phosphates due to the ratio in which they are consumed. GFO corrects this imbalance by removing the remaining phosphates. Don’t worry, the bacteria is far more effective than GFO at consuming nutrients, so you usually won’t end up with excessive nitrates because the GFO adsorbs the PO4 first.
