Small inflatable and plastic pools are typically filled with tap water. Some people in the United States have a disinfectant in their tap water but this is not adequate to kill germs that may get into water used for swimming. Sources of information exist about how to disinfect these pools.
Foods rich in vitamin E and C will boost the immune system, so all types of citrus fruits, strawberries, kiwi, cauliflower, mustard greens, lettuce, turnip, tomatoes, wheat grass and avocados should be consumed regularly by people having a low platelet count.
1 Myelosuppression - a decrease in the production of blood cells, which may lead to low blood count.  Pancytopenia - a lowering of all three types of blood cells; red blood cells, platelets, and white blood cells, which may lead to low red blood cell count, low blood platlet count, and/or low white blood cell count.