If there is no fecal matter in the pool you can see, you merely need to raise the free chlorine level to the recommended shock level for the level of CYA, ie,Stabilizer, in the water. For example, if your CYA level is 30ppm, you need to raise the Free Chlorine level to 15 ppm for at least 24 hours. Then it should be safe.

If Ben, aka, PoolDoc, amends that, follow his recommendation.