All but a small volume of the holding water (approximately 5%) is removed by siphoning and replaced slowly over a 10 to 15 minute period with dilution water.
A large volume of water is removed and not replaced
mnli hypothesis: A large volume of water is removed and not replaced premise: All but a small volume of the holding water (approximately 5%) is removed by siphoning and replaced slowly over a 10 to 15 minute period with dilution water.