- Drum washers or mechanised brushes.
- Machine washing.
Key Factors Positive
- Drum washers are cheap and can be home-made.
- User friendly.
- Machines last from 5 -15 years.
- Services can be contracted out to cleaning stations on a region scale, so the cost for cleaning infra-structure does not have be taken on by every small to medium sized operation.
Key Factors Negative
- Damage or mortality of stock can occur (up to 20% of total stock).
- Long line mussels have thin shells which may be prone to breakage during this process.
- Labour costs can be high (5 - 30% of total costs).
- Cleaning procedure involves transfer of stock to clean nets, which can involve stress and mortality.
- 5 to 40% of total person hours.
- 5 to 30% of total costs.
- 2 to 20% of the stock can be lost.
- This can be a relatively expensive strategy if carried out many times in a year. Combining with other strategies such as air drying and disk washing brings the frequency of cleaning down and can result in savings of up to 50% of the cost per sq. metre of netting, from case studies of the farms involved in the CRAB Project (see more details in the Best Practice Guidelines).
- Procedure needs to be repeated every 8 weeks during the fouling season or just before selling.
- Effectiveness is variable with good success rates with algae and hydroids but not with barnacles and tubeworms.
- If nets are left to dry for around 2 weeks prior to cleaning, machine washing removes all fouling effectively.