There are a few things you can do to clean the bottom of a pool:

  1. Use a plunger to suction onto the bottom of the pool and pull. This will cause the water to flow out from under the object and clean it.
  2. Use a vacuum cleaner with the hose attachment to suck up all of the dirt, dust, and other debris that has built up on top of the pool. This will also clean any areas that have been contaminated by bacteria or other pollutants.