system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
True about slow sand filter is -
assistant
The correct answer is  Option A - wrong, slow sand filter occupy more space Option B - wrong, it is less expensive Option C - correct, rate of filtration is very slow (2-3m.g.a.d.) hence takes longer time Option D - wrong, effective sand size in slow sand filter is 0.2-0.3 mm (PARK TB 25th edition pg 773)