Designing a hatchery’s water system
Written by Niek Yntema, Projectmanager Pas Reform
The importance of water in the hatchery is well understood. Without water, washing/cleaning is practically impossible and many HVAC systems use water to provide optimal conditions for eggs, embryos, chicks and personnel. Sub-optimal water quality and insufficient water supply can cause losses, by undermining hatching results, contributing to mechanical breakdowns and presenting hygiene risks.
A properly designed water system is therefore critical to the success of any hatchery - and since good water is generally becoming more scarce and costly, it has become increasingly important to understand how to optimise the hatchery’s water quality and supply.
Typical water analysis.
A good hatchery water system starts with knowing the quality of the water source. This is commonly achieved by (regular) laboratory analysis, with typical parameters including:
Acidity/alkalinity (pH): A pH of 7 is neutral. Below 7, the water becomes acid (can cause corrosion) while above 7 means the water is alkaline (can indicate hard water due to high levels of calcium). Generally a pH of 6-8 is acceptable - and pH can be corrected by adding chemicals.
Total hardness is an indication of hard water, which can cause limescale build-up, resulting in inefficiencies or the breakdown of equipment. The most common unit used is °dH (German degree) or mg CaCO3/l. Generally, 2-6°dH (35-107 mg CaCO3/l) is advised, with a maximum of 2°dH recommended for nozzle/spray humidification. Water softeners are used to reduce water hardness.
Suspended particles should be absent, as these will block pipes, nozzles etc. Suspended solids are removed by filters.
Microbial contamination should be absent. If water is contaminated, another source should be used. Disinfection can reduce contamination, but for example, using water contaminated with Pseudomonas, Acentobacter, Proteus, yeasts or molds - even after disinfection - for humidification is not advised.
Some elements in water are known for aggressive reactions which cause the discolouration of equipment. Commonly, the following thresholds are used: the total sum of chloride and sulphate (Cl & SO4) max 200 mg/l, Magnesium (Mg) max 50 mg/l, Iron (Fe) max 0.02mg/l. These elements require specific treatments. Extremely pure water (for example distilled or Reverse Osmosis water) is also known to be aggressive. It is therefore advisable to build a small bypass into the system.
Water treatment systems
Depending on the differences between the results of water analysis and the hatchery’s requirements, water treatment may be needed. Typically, water treatment is implemented using modular units:
- Filtration eliminates suspended solids, usually by means of cartridge and/or sand filters;
- Chemical treatment: usually anti-bacterial and anti-scaling treatments and/or a UV disinfection unit;
- Water softener, which reduces water hardness by replacing calcium and magnesium with sodium;
- Reverse osmosis, which uses membranes to separate dissolved salts, producing pure water;
- Pumps, sensors and control units, to monitor equipment function, with buffer tanks to balance the difference between supply and demand. Reject or backwash water needs to be drained.
Water sources for the hatchery
In urban or industrial areas, water is generally supplied by the city’s main utilities provider or “city water”. The quality of city water varies, from excellent potable water (comparable with bottled water) to undrinkable,...
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