Last year, there was much excitement about our new large-scale exhibit, which we had hoped to open in December. Unfortunately, we have hit a few delays, which involve some critical elements in the construction process. It is important for us to deal with these issues at this stage, rather than further down the line when the exhibit is filled with water and stocked with animals. We are disappointed that we have not yet been able to open the doors to the exhibit, but you’ll be the first to know when we are ready and we hope that the wait will be worth it!

As mentioned in a previous blog, the construction and fitting out of a large-scale aquarium exhibit is no mean feat and requires considerable design, planning and expertise. Now, let us tell you about another critical element in an aquarium: life support. In a large exhibit this has to be thoroughly thought through and carefully planned as it involves extensive piping, much of which is laid down beneath the concrete floor of the exhibit.

Underfloor piping being layed

Several prerequisites must be met to ensure the survival of marine animals and plants in an artificial environment. These include life-support systems (LSS) to maintain the required water quality parameters, which include oxygen levels, constant pH levels and the removal of animal waste products, which can become toxic.

Drum filter waiting for installation

Behind the scenes of the Aquarium, the LSS comprise an assortment of filters, heat exchangers, pumps and skimmers, which operate continuously amid a complex maze of pipes. The water quality of the exhibits is monitored daily to ensure that all the animals remain healthy. Water temperatures are also checked regularly, as fluctuations can be fatal for the animals.

Sand filtration control valves

The LSS for the new exhibit was designed and installed by Aquarium staff, which not only saved us hundreds of thousands of rands on specialist engineering fees, but also gave us an opportunity to train our technical staff. This system will be five times more effective than the current filtration on the I&J Predator Exhibit. We also built and designed our own protein skimmers to save costs and to incorporate elements which, from our experience, would increase efficiency.

Four homemade protein skimmers

There are three main loops (rings): sand filtration, protein skimming and drum filtering. Heating is a side loop to the protein-skimming system and pH-control is a side loop of the sand-filtration loop. Drum filters are mechanical filtration and deal with solid waste, that is, the particles that float around in the water.

Pumps driving the drum filter and protein skimmers

Life-support systems can be one of the main consumers of energy in aquariums. To reduce consumption we have put variable-speed drives on all of our large pumps, and piping has been chosen to reduce friction as friction reduces flow rates and increases pumping requirements. We are also using waste heat from the chillers to heat the new exhibit. 

Ninety percent of the equipment for the new LSS was purchased from local suppliers, but we had to import the sand filters and instrumentation as large fibreglass sand filters are not available in South Africa and the instrumentation is aquarium-specific and tried and tested to last in our environment.

A large sand filter is delivered to the Aquarium. Sand filters are responsible for cleaning particles from the water much the same as your pool filter does

We have installed a new saltwater-intake from the harbour to allow for the increased water requirement for the new exhibit (which will hold 1.5-million litres of seawater) and this will allow us to increase water flow to other exhibits too.

Continuous water flow ensures that the contents of the system are currently replaced every 10 days. Water is pumped at a rate of 40 000 litres (up to 60 000 when the new system is up and running) per hour from the harbour into the Aquarium and the water in all the exhibits is recycled completely every two hours.

LSS piping feeding the protein skimmers and drum filter while being installed
blog comments powered by Disqus