Post split for better exposure..
When adding new sand to an established or new tank, the results are pretty much the same. You will get some cloudiness due to the fine dust particles in the sand. Regaular base sand will also not have the added weight of bacteria to help settle it faster and does take additional time.
I would leave the filter going as is. It will actually improve the water quality faster. Feep the media clean as it will "clog" and reduce efficiencey. The skimmer (if used) will also help remove the particles.
Did you place the LS
on top of the playsand or where they mixed? How many inch's of sand where already in the tank and how much depth was added with the new 60lbs of sand?
If increase too quickly, you may have also inadvertantly smothered the aerobic bacteria and could be experiencing a bacterial die off bloom. Sand should really be added only about ˝" per day (for an established tank) to allow the animals and bacteria in the old sand time to adapt. Running the tests for water quality may answer that.