Water Testing Strips like the AquaChek Test Strips can be used to test for individual chemicals or you can buy something like AquaChek Select 7 Way Test Strips or Yellow 4 Way Chlorine to make multiple tests at the same time.
Most second-language speakers reside in Francophone Africa, in particular Gabon, Algeria, Mauritius, Senegal and Ivory Coast. In 2015, French was estimated to have 77 to 110 million native speakers, and 190 million secondary speakers. Approximately 274 million people are able to speak the language. According to a demographic projection led by the UniversitÃ© Laval and the RÃ©seau DÃ©mographie de l'Agence universitaire de la francophonie, total French speakers will number approximately 500 million people in 2025 and 650 million people by 2050.
The Numbers of Spanish Speakers in the World Exceeds 500 million July 26, 2014 The chart below gives data by country of the 460,368,652 native Spanish speakers in the world and 517,423,452 million who speak Spanish including those who speak it as their second language. There are at least 70 countries in the world with measurable Spanish speaking populations. At least 29 countries have more than 1 million Spanish speakers.