Universitad Autonomo Mexico – Multi-Stress System

Institution:
Location:	Sisal, Hunucma, Yucatán, México
Contact:	Dr. Carlos Rosas Vaquez
Equipment:	Four Multi-Stressor Units
Habitats:	Fresh water & Seawater;
Temperature:1	15° to 35° C;
Description:	Parameter Specification Number of 1-L tanks (1.5L) Total volume per unit 14 tanks 21L Number of 3-L tanks (2,8-L) Total volume per unit 12 tanks 34L Number of 9-L tanks (9.35-L) Total volume per unit 6 tanks 56L Total volume per unit with 9-L tanks (L) 56L + 22L= 78 (22L is the water within Filtration Module, pumps & plumbing) Total volume par unit with 3-L tanks 34L+22L =56 L Total volume par unit with 1.5-L tanks 21L+22L =43 L Filtration module flow (LPH) 840 liters per hour Habitat maximum flow (LPH) 600.  This flow is manually adjustable.  ATTENTION! TOO MUCH FLOW REDUCTION WILL DAMAGE PUMP Water turnover per hour in rearing tanks per unit    (at maximum inflow- 600 Liters/h). The minimum circulation water flow for all tanks is 200 Liters/h. Tank volume Water turn-over at maximum flow (600 lph) Water turn-over at minimum flow    (200 lph) 9.35L 11 4 2.80-L 18 6 1.5L 28 10 System temperature range (°C) 15 – 35 Factory tests were done at room temperature of:  (°C) 25 Water flushing rate with make-up water pump and automatically controlled by the Monitron 5 to 100% (% of the total unit volume per day) Filtration module volume (liter) 22 Monitoring & Control Temperature, water make-up flow, dissolved oxygen Biofilter (NH3 mg/l) non-ionized (target)* Cold water:≤ 0.0125 mg/L Warm water: ≤ 0.02 mg/L Biofilter (N-NO2 mg/l) (target)* <0.2 Biofilter (NO3 mg/l) (target) <13
Water recirculation level:	99.7% (1 water exchange/5 to 6 days);
Work done:	Conception Fabrication On-site assembling, commissioning and training

Universitad Autonomo Mexico – Multi-Stress System

Unique in the industry, the Multi-stressor system is the outcome of several years of R&D and careful design.  It provides the means of adjusting one, or more, environmental parameter independently of the others. Aquatic and marine organisms are exposed to precise, stable and reproducible environmental conditions.  We hope this member of the AquabioLab family and will contribute to propel your research.

In a nutshell here is the main Multi-stressor’ features:

• Dynamic control of water temperature between 15°C and 35°C;
• Generates hyperoxic conditions up to 110% saturation (if you connect an oxygen cylinder);
• Generates hypoxic conditions down to 20% saturation;
• While under hypoxic conditions:
  • an automatic mix of air and nitrogen provides constant degassing action, protecting the animals from buildup of CO₂ gas;
  • your animals are protected against accidental drop of dissolved oxygen below the set point by automatically raising the level of oxygen to 80% saturation when/if this happens;
• Provides automatized control over make-up water flow (incoming new water in each Multi-stressor unit);
• Provides manual control over the water flow to each row of rearing tanks.
• Constant protection against nitrogen super saturation (a constant risk in pressurized systems) by the use of a trickling biofilter operating at ambient pressure.  Counter-current air flowing through the biofilter prevents nitrogen super saturation.
• Multi-stressor units are designed to operate in highly recycled water.  The biofilter media is pre-activated with live saltwater nitrifying bacteria before delivery.  This significantly reduces biofilter maturation time.

Universitad Autonomo Mexico – Multi-Stress System : Flow circulation

The water flow through a Multi-stressor unit is divided into two circuits, the Filtration circuit (for the Filtration module) and the Circulation circuit (for the Habitat module).

Filtration Circuit

From the sump tank, the water is pumped through a 20 microns cartridge filter and the activated carbon filter. From the activated carbon filter, the water flows through the chiller & heater, the biofilter and trickles down back to the sump.

Circulation Circuit

The water coming from the biofilter is collected in the sump and then is pumped directly to the rearing tanks.  The effluent from each of the rearing tanks flows along a gutter and then back into the sump tank.

A double hydraulic circuit assures a constant flow to the rearing tanks, regardless of filter clogging.

Water distribution lines

The standard water distributor assembly dispatches water to the 9L and 3L tanks. This removable line is easily replaced by the 1L distributor assembly for the 1L tanks.  Simply unscrew the union, and gently pull out the assembly.

Universitad Autonomo Mexico – Multi-Stress System : Temperature control

The cooling and heating capacity of the unit was factory-tested in freshwater (Table 4).  A minimum temperature of 15°C and a maximum of 34°C were obtained in fresh water (room temperature at 25°C).

Without cooling or heating, a room temperature of 20°C, and pumps operating, the temperature of unit 1 at equilibrium is 23.2 + 0.1°C and is at 24.5 + 0.1°C for unit 2. This temperature is higher than room temperature due to the heat transfer from the pumps to the water. Therefore to obtain a cooler temperature than these balanced values, the chiller must be operated. Likewise to obtain a warmer temperature than these balanced values the heater must be operated.