High schoolers comprehend the interactions of pH, alkalinity, hardness, and carbon dioxide in aquaculture water. They read the SRAC fact sheet number 464 "Interactions of pH, Carbon Dioxide, Alkalintiy and Hardness in Fish Ponds." Students define the term pH? They answer questions after the reading such as: What pH range is considered acid? High schoolers take water samples from the varios sources. They record the of the samples when they are taken.