What aspects need special attention during a process of cleaning a hydro-cooling system?

What are criteria for determining completion of cleaning a hydro-cooling system?

What are steps to clean a hydro-cooling system?

What are requirements before cleaning a hydro-cooling system?

The operation guide for hydro-cooling miners suggests that the liquid inside the miners should be completely drained during storage and transportation. If the miners are suddenly or temporarily taken out from cabinet and the liquid in the miners is not completely drained, what impact will it have?