A quick Google search yielded the following from an Intex FAQ site:
"3.) Can we use the pool while the filter pump is operating? Is it safe?
Yes, if the pump is operated according to the manual, and with proper GFCI installation. The Model M1 is the exception to this rule and should not be operated while using the pool."
A quick Google search reveals the Model M1 is a 300 gph and is sold with the 8 foot Intex.
However, my pump is a 530 gph and here is what the manual says: "Filter system can be used as many hours as desired, but NEVER when the pool is occupied." (emphasis in the original).
As far as I know there is no way on this device to have the pump operating and not the filter system. That is why I included the suggestion to not swim with the unit on. The manual also stresses to NEVER use an extension cord. I don't think I know a single user who abides by that directive. Not sure if using an extension cord makes it more prudent to turn the pump/filter off before swimming or not, but it does make me more nervous.