Cleaning your rain water tank without the need to empty your tank. Your tank can be cleaned full or with partial water.
The process used is a vacuum system to remove build-up of sludge from the bottom of tank with minimal water loss.The remaining water is sanitized and pumped through a filtering system to remove any remaining contaminants.
Government departments recommend tanks to be have sludge build up treated every 2-3 years
In Australia where water is scarce, our limited rainfall is too valuable to waste.
Rainwater is generally safe to drink but collecting a good clean supply depends on "low maintenance -- not no maintenance"