(1) Acceptable water clarity of a pool, spa, or other water feature shall be maintained at all times. It shall be determined by one of the following methods:

(a) when standing anywhere on the perimeter or deck of the pool, spa, or other water feature, the grates on the main drain(s) at the deepest portion of the pool floor must be clearly visible and sharply defined at all times; or

(b) water must, at all times, have sufficient clarity so that a black disc, six inches in diameter, and placed on a white background in the deepest point of the pool, spa, or other water feature, must be clearly visible and sharply defined when viewed from any point on the deck within five feet of any pool edge.

(2) When the licenseholder or operator disputes the department's determination that a pool, spa, or other water feature does not meet clarity requirement as defined in (1), the department may use an NTU reading to make its final determination. A pool will be determined to have sufficient clarity only where the NTU reading is 1.0 NTU or less.

(3) Clarity readings shall be marked daily on the log sheets for the facility. Clarity readings are defined by the following terms:

(a) "excellent" means that the water is sparkling clear or it has an NTU reading <.5;

(b) "good" means that the water is clear to very clear or it has an NTU reading of 0.5-1.0; and

(c) "poor" means the water clarity is significantly deteriorated so that the main drain cannot be seen clearly or the bottom of the pool is obscured, or the water has an NTU reading in excess of 1.0.