Since excess nutrients from either point (a single identifiable origin) or nonpoint (runoff) sources enter waterways, their control is the best method for reducing the presence of algal blooms. Decreasing the amount of nutrients from agricultural and landscaping runoff, better management or elimination of CAFOS (concentrated animal feeding operations), dam removal, and water reuse are methods to keep waterways healthier. Prevention is the best solution, but when algal blooms do occur, there are methods to mitigate their effect on waterways. Physical controls include aeration, hydrologic manipulations, mechanical mixing, surface skimming, and ultrasound. Chemical management of algal blooms include the use of algicides, barley straw, coagulation, and flocculation. Steps to control climate change will also help decrease the occurrence of problematic algal blooms.