Being an indoor pool my guess is poor ventilation and insanely out of balance pool with very high CYA and very high chlorine numbers. It seems many motels have no idea how to maintain their pools, the responsibility goes to a handy man, or even a front desk clerk, the attitude of a little is good a lot is better seems to be very common. I know of one small golf resort in my area that uses 2 quarts of expensive concentrated blue clarifier per day to maintain there pool. (I don't know the exact size pool, would guess under 50,000 gallons.
