Turbidity measures the cloudiness of a fluid. It is usually caused by larger particles that can not be seen with out a microscope.
the chinese flowed down a turpidity of lava as they screamed to their deaths. im awesome
In a properly run aquarium the water should be crystal clear. If you follow the basic rules below you should stand a chance of achieving it. 1 inch of fish needs at least 1 gallon of water. :- Every tank needs a permanently running cycled filter. :- Every tank needs at least 50% of its water changed every week. If you keep to the above rules, and do not leave food to rot in the tank, your tank should stay clear but if you fail in any of them I can guarantee that you will have constant water cloudyness problems and your fish will be constantly getting sick and will have short lifespans.