Even though the Georgia Aquarium's tanks hold 8 million gallons of water, the facility uses only as much water as an average supermarket. A treatment and reclamation system cleans and recycles the water, losing only a little to evaporation and the protein skimmers that help remove debris.
Behind the scenes, the aquarium uses three types of filtration:
- Mechanical filtration, which removes fine particulates
- Fractionation, which removes dissolved organic materials
- Ozone, which plays the same role as chlorine in a swimming pool but is safer for fish
It takes 218 pumps, 141 sand filters and 70 protein skimmers to do this for the whole aquarium. These pumps move 261,000 gallons of water per minute -- that's about 163,125 toilet flushes. Ocean Voyager alone requires 28 pumps and 56 sand filters, which clean about 1,800 gallons of water per minute. The life support staff must perform maintenance, including oil changes and filter changes, on all of these pumps and filters.
The life support staff also measures tank turnover time -- the amount of time it takes for all the water in a tank to be filtered and cleaned. The staff's goal is to keep the turnover time under two hours. Flow rates also affect the dissolved oxygen in the tanks -- the fish will suffocate if there is too little, but too much can be toxic.
All these pumps send water through a series of filters and skimmers. Even though this process is necessary, it can also create some problems. We’ll examine filtering and monitoring in the aquarium’s life-support systems in the next section.