Knowledgebase > Probiotics: What Are They and What Do They Do? By Murray W. Camp
Advanced Search


Getting Started
Educational Articles

Ask a Question
Email Specials
Subscribe to our newsletter feed.
Newsletter Tips & Tricks! New Products!
Discounts & Promos!
Clearance Items - Save now while supplies last! Gift Certificates
Q11191 - INFO: Probiotics: What Are They and What Do They Do? By Murray W. Camp
Adequate control of dissolved nutrients in reef aquaria has long been the bane of reef keepers. Large periodic water changes, massive amounts of live rock in the display, deep sand beds, algal filters, and expensive amounts of chemical media have all been recommended as tools in the battle against dissolved nitrates and phosphates. All of these tools have merit.

Over the last few years, however, many reef aquarists have embraced a more bacteria-centered approach utilizing what are termed "probiotic methodologies" to proactively manipulate the microbial communities involved in nutrient processing in aquariums. Almost all of the methodologies involve providing a source of organic carbon to "feed" the bacteria. Some of them also utilize periodic inoculation of bacterial strains, and some of the more involved systems also utilize certain minerals, called zeolites, in an up-flow reactor.

Dosing of an organic carbon source is the core principle in almost all probiotic methodologies. The purpose of doing so is to raise the amount of dissolved organic carbon (DOC) in our systems, especially types of DOC that are readily utilized by heterotrophic bacteria. Heterotrophic bacteria, in contrast to photosynthetic autotrophic bacteria, must assimilate organic carbon as a food source from the surrounding water, in addition to nitrogen and phosphorus sources, in order for cellular metabolism to occur. As a result of the growth of these organisms, complex microbial communities, called biofilms, are formed. Sources of nitrogen, in the form of nitrate ions, and phosphorous, in the form of phosphate, are readily bioavailable in most marine aquaria. Many reef aquaria may be carbon limited, at least in terms of types of organic carbon that are easily utilized by heterotrophic bacteria. The solution, then, is to add a source of organic carbon that can be easily utilized by heterotrophic bacteria. As these microbial communities grow (the carbon limitation having been removed by the addition of an appropriate carbon source) they will also uptake nitrates and phosphates, thus reducing the concentration of these nutrients from the water column.

So the next question becomes: what are appropriate sources of organic carbon? Many marine aquarists have used vodka, vinegar, or other readily available materials. Alternatively, many packaged systems exist that include not only the organic carbon source, but also other components that may enhance the effectiveness of the methodology. These systems include those manufactured by Prodibio, Zeovit, and PolyLab, and also include the multiple types of biodegradable polymers ("biopellets") available.

About the Author

Murray Camp is a reef aquarist with over seventeen years' experience in keeping marine aquaria, from 5 to 800 gallons. He is also a nationally recognized speaker who presents at reef conferences and events around the country, and is an author whose articles have appeared in CORAL Magazine and other publications.

In addition to moderating the TEAM Marine Depot forum on Probiotics and Labile Organic Carbon Dosing, he serves on the Board of Directors of MASNA—the Marine Aquarium Societies of North America—where he is actively involved in conservation and legislative issues.

Related Articles
No Related Articles Available.

Article Attachments
No Attachments Available.

Related External Links
No Related Links Available.
Help us improve this article...
What did you think of this article?


Tell us why you rated the content this way. (optional)
Approved Comments...
Been keeping reefs for 25 years, had a big hair algae outbreack about a year ago and started carbon dosing with vodka and the tank has never been more stable. Approved: 9/21/2012
Article Details
Created on 9/19/2012.
Last Modified on 1/15/2014.
Last Modified by Dot Yuson.
Article has been viewed 6977 times.
Rated 9 out of 10 based on 12 votes.
Print Article
Email Article