Aquatic Life Support Systems

Ozone (O₃) is a crucial component of aquatic life support systems in zoos, aquariums, and wildlife rehabilitation centers. Ozone is used for water purification, pathogen control, and air treatment to create healthier environments for animals. Due to its powerful oxidizing properties, ozone effectively eliminates contaminants, neutralizes harmful bacteria and viruses, and improves overall water quality.  Ozone leaves no residuals or chemicals in the water, only elevated dissolved oxygen levels.

How Ozone Is Used in Aquatic Life Support Systems:

Ozone Generation:

- Ozone gas is produced on-site using ozone generators. Ozone is produced from oxygen at high concentrations to be efficiently dissolved into water.  Ozone must be produced on-site with this mechanical equipment and is produced as it is it used.

Ozone dissolved into Water:

- In aquatic systems, ozone is via a venturi injector or diffuser, where it dissolves and interacts with the water. The dosage is carefully controlled via dissolved ozone meters or ORP meters to balance effectiveness with safety for animal life.

Oxidation and Disinfection Process:

- Once dissolved, ozone reacts with organic and inorganic contaminants—such as ammonia, nitrites, bacteria, viruses, and fungi—breaking them down into harmless byproducts like carbon dioxide, water, and oxygen. This process, called oxidation, eliminates pollutants without leaving toxic residues.

Filtration and Residual Removal:

- After treatment, water passes through additional filtration (e.g., sand filters or protein skimmers) to remove oxidized particles. Any residual ozone is removed using degassing units, UV Lights or activated carbon filters, converting it back to oxygen to prevent harm to animals, as excess ozone can damage gills or tissues.

Monitoring and Control:

- Advanced Aquatic Life Support Systems integrate sensors such as ORP monitors, or dissolved ozone monitors to regulate ozone levels, ensuring they remain effective (typically 0.1–0.5 ppm in water) without exceeding safe thresholds for animals or staff.

Benefits of ozone use in Aquatic Life Support Systems:

Superior Water Purification

- Ozone removes organic waste, ammonia, nitrates, and heavy metals from water, ensuring safe, clean environments for aquatic animals.

- It enhances water clarity by breaking down particulates, tannins, and dissolved organics, providing a crystal-clear view in aquariums and zoo exhibits.

- Ozone is one of the strongest disinfectants known and leaves no residual, only oxygen. Ozone is effective at killing pathogens like E. coli, Salmonella, and parasites without the need for harsh chemicals. This reduces disease risk in densely populated exhibits, where infections can spread rapidly.

Water clarity and quality

- By oxidizing organic matter (e.g., fish waste, uneaten food) and micro-flocculating fine particles, ozone enhances water clarity, improving visibility for visitors and light penetration for photosynthetic organisms like corals. It also breaks down yellowing compounds (e.g., tannins), keeping water crystal clear.

Pathogen and Disease Control

- Ozone destroys bacteria, viruses, fungi, and parasites

- It is highly effective against waterborne diseases, such as Ichthyophthirius multifiliis (Ich) in fish and Aeromonas infections in amphibians.

Reduction of Chemical Usage

- Unlike chlorine, ozone leaves no harmful residues and does not form carcinogenic byproducts like chloramines or trihalomethanes (THMs).

- It reduces the need for antibiotics and other chemicals, leading to a more natural and sustainable life support system.

Increased Oxygen Levels

- Ozone breaks down into oxygen, improving the oxygen content in water and air.

- Higher oxygen levels lead to better respiratory health and improved immune function in animals.

How is Ozone Applied in Different Environments:

Public Aquariums & Marine Life Exhibits

- Used in recirculating aquarium systems (RAS) to maintain high water quality.

- Oxidizes organics such as fish waste, uneaten food, and bacteria, preventing the spread of diseases.

- Helps maintain optimal pH balance and dissolved oxygen levels.

Example Use Case:
Large aquariums like SeaWorld and Monterey Bay Aquarium use ozone in filtration systems to keep water pristine for dolphins, sharks, and coral reef exhibits.

Zoo Animal Water Features & Ponds

- Ozone is applied in hippo, penguin, and sea lion pools, ensuring clean and odor-free water.

- Prevents the growth of algae, harmful bacteria, and biofilms.

Example Use Case:
Zoos with large animal water exhibits (e.g., elephants, tigers, and polar bears) use ozone to prevent waterborne illnesses.

Life Support for Sensitive & Endangered Species

- Ozone eliminates toxins that could harm endangered species, such as amphibians and marine mammals.

- Ensures pathogen-free environments for sensitive species in breeding programs.

Example Use Case:
Manatee rehabilitation centers use ozone to prevent infections and improve survival rates for injured animals.

Wastewater & Veterinary Facilities in Zoos

- Ozone is used to treat wastewater from animal enclosures, reducing harmful pathogens before discharge.

- Veterinary centers use ozonated water for wound cleaning and disinfection in injured animals.

Example Use Case:
San Diego Zoo’s veterinary hospital uses ozone for cleaning

Case Studies of ozone used in Aquatic Life Support Systems:

Potential and Limitations of Ozone in Marine Recirculating Aquaculture Systems: Guidelines and Thresholds for a Safe Application

Authors: J. Scroder

Abstract

 

Read the full study here.

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The Practical Use of Ozone in Large Marine Aquaria

Authors: Nestor G. Ramos & James F. Ring

Abstract

The use of ozone as a disinfectant in large marine aquaria life support systems is discussed. The advantages and disadvantages of ozone and the author's practical experience in its application to open and closed marine life support systems are presented.