| Performance goal: Treatment achieves an optimal water hardness for optimal bird health and scale minimisation. |
|---|
| Description: Hardness is associated with bicarbonate, sulphates, and calcium carbonate. These substances release hydroxyl ions (OH-) when dissolved in water and are principally bicarbonate (HCO3) ions and carbonate ions (CO32-). These compounds act as buffers in water; that is, they buffer the water against sudden changes in pH. Hardness causes scale, which reduces pipe volume and makes drinkers hard to trigger or leak and it can corrode cool cell pads. High concentrations can also give water a bitter taste that birds don’t like. Hardness can reduce the effectiveness of soaps, disinfectants and the administration of some medications. |
| Performance criteria: Optimal water hardness is maintained, and scale accumulation is minimised. Best practice levels: hardness 0–100mg/L, calcium 0–60mg/L, magnesium 0–14mg/L, sulphates 0–40mg/L, iron 0–0.2mg/L, manganese 0–0.01mg/L Maximum acceptable levels: hardness 0–200mg/L, calcium 0–600mg/L, magnesium 0–125mg/L, sulphates 0–250mg/L, iron 0–0.3mg/L, manganese 0–0.05mg/L |
| Minimum requirements |
| Measure hardness monthly. |
| Measure calcium, magnesium, sulphates, iron and manganese quarterly. |
| Best practice options |
| Nutritionists consider calcium, magnesium, sulphates, iron and manganese concentrations in the water when formulating diets. |
| If concentrations are above maximum acceptable levels, a pre-treatment to lower salts is applied to drinking water. See Table 16 (below) for a comparison of the effectiveness of pre-treatments against hardness. |
| Do not use ion-exchange if the water is already high in sodium unless using potassium chloride instead of sodium chloride. |
Table 16. Effectiveness of pre-treatments against hardness
| Effectiveness against hardness | Hardness | Calcium | Magnesium | Sulphates | Iron | Manganese |
|---|---|---|---|---|---|---|
| Pre-treatment | ||||||
| PP filter | – | – | – | – | – | – |
| Ceramic filter | – | – | – | – | – | – |
| Pleated filter | – | – | – | – | – | – |
| Rapid sand filters | – | – | – | – | – | – |
| Semi-rapid sand filters | – | – | – | – | – | – |
| Slow sand filters | – | – | – | – | – | – |
| Centrifugal filtration | – | – | – | – | – | – |
| PAC | – | – | – | – | – | – |
| GAC | – | – | – | – | – | – |
| BAC | – | – | – | – | – | – |
| Ion-exchange resins | MH | MH | MH | MH | MH | MH |
| Chemical coagulates | L | – | – | – | – | – |
| Lime softening | M | MH | MH | M | M | M |
| Chemical oxidation | L | – | – | MH | MH | MH |
| Reverse osmosis | H | H | H | H | H | H |
| Nanofiltration | LM | LM | LM | LM | LM | LM |
| Ultrafiltration | – | – | – | – | – | – |
| Microfiltration | – | – | – | – | – | – |
| Electrodialysis | MH | MH | MH | MH | MH | MH |
| Electrodialysis reversal | MH | MH | MH | MH | MH | MH |
| Capacitive deionisation | MH | MH | MH | MH | MH | MH |
| Membrane capacitive deionisation | MH | MH | MH | MH | MH | MH |
| Aeration | L | – | – | LM | LM | LM |
| Electronic water conditioning | L | L | L | L | L | L |
| L: low, LM: low to moderate, M: moderate, MH: moderate to high, H: high, –: N/A | ||||||
