The American University in Cairo – Wet Table

The American University in Cairo – Wet Table

Institution:
Location:	Cairo, Arab Republic of Egypt
Contact:	Dr.  Justin R. Grubich
Habitat:	Freshwater & Seawater
Type of rearing unit:	Wet table Filtration Module & Habitat Module
Unit description:	The Wet Table is an apparatus for use in research, consisting of a Filtration Module (sump, pump, bio-filter, cartridge filter, etc…) and a Habitat Module (holding tank & plumbing). The Wet Table is capable of accommodating up to six aquaria of 30 litres each for a total of 180 L. These aquaria (or any other similar tank of approximately the same capacity) are situated on the fiberglass grating. One series of six refill valves allows water to enter the aquaria; another series of six valves allows air to enter them. The four fiberglass grids are removable.
Mandate:	Conception Fabrication

The American University in Cairo – Wet Table

The American University in Cairo – Wet Table: Flow circulation

The water flow through the unit is divided into two pressure fed circuits: the Filtration Module circuit and the Habitat Module circuit. Each circuit is fed by its own pump. Note that the Habitat Module circuit is provided with a back-up pump. The unit, thus, is provided with a total of three pumps.

From the sump tank, the water flows into these two circuits. The Filtration Module circuit directs the water through the cartridge filter, activated carbon/aragonite filter and bio-filter; while the Habitat Module circuit directs the flow through the rearing tanks (aquarium and holding tank).

The water-heater, temperature probe and make-up water inlet are situated in the sump. Make-up water enters in the system via a float valve. This float automatically maintains the water to a level below that of the system overflow.

The American University in Cairo – Wet Table: First Circuit (Filtration module)

From the sump tank, the water is pumped through the 20 micron cartridge filter and the activated carbon/aragonite filter.  From the activated carbon filter, the water flows through a flow monitor.  If the monitor detects zero flow past it, the temperature controller automatically shuts off the heater

From the flow detector, the water flows through the bio-filter and returns to the sump. A flow-meter at the pump outlet measures the rate of flow and a control valve downstream of the flow-meter controls it.

The American University in Cairo – Wet Table: Second Circuit (Habitat module)

From the sump, the Habitat Module pump directs the water through a control valve and Rota meter type flow-meter. These enable the operator to check the flow and adjust it. The water then flows into the distribution line. The distribution header is furnished with a standpipe. The standpipe provides a steady head of water independent of the number of header valves that are open. The standpipe is open at the top in case of overflow. The water falls from the header pipe into each tank, from here it is returned to the sump via a 600 micron filter bag.

The water level in the holding tanks can be controlled by means of an overflow. However, there is no need to install this overflow unless the user wishes to keep biomass in the holding tank.

The Habitat Module circuit main pump is provided with a back-up. In case of a main pump failure, the operator can quickly switch to the back-up pump. Note: the three unit pumps are identical and hence are interchangeable.