Context Urine comprises water, salts, and waste products from the kidneys. The balance of these compounds can affect the urine's acidity levels, which specialists measure in pH. According to the American Association for Clinical Chemistry, the average value for urine pH is 6.0, but it can range from 4.5 to 8.0. Urine under 5.0 is acidic, and urine higher than 8.0 is alkaline, or basic. Different laboratories may have different ranges for "normal" pH levels. The laboratory report will explain the normal and abnormal levels for the specific laboratory. If a person has a high urine pH, meaning that it is more alkaline, it might signal a medical condition such as: kidney stones, urinary tract infections (UTIs), kidney-related disorders. If a person has low urine pH, meaning that it is more acidic, it might indicate a medical condition such as: diabetic ketoacidosis, which is a complication of diabetes, diarrhea, starvation. Acidic urine can also create an environment where kidney stones can form. Content The dataset is formed by a single 60 years old man, which is diagnosed with initial stage of kidney stones. Doctor recommended to keep pH level on average level (pH: 6.4 - 6.8) to stop forming of new stones and drink more water to get rid of already formed stones. pH level was measured with "PH-02" device (Measuring range: 0.0 - 14.0 pH, Measurement accuracy: ± 0.1 pH). Measurements of pH were made on everyday basis almost without erros or misses on track. With pH measurements all the food (and some other conditions like gym) were accurately logged. Dataset consist of 2 parts. First part was logged from 06.09.2017 to 05.04.2018 on daily basis. e.g. no exact time of pH measurements or time of eating were recorded. Only day is available. File: ph_v1_days.csv Second part logged from from 09.04.2018 to 25.09.2018 with exact time of day when measurement was made. Files: prods.csv and phlist.csv Inspiration Predict what combination of products is best to eat to keep pH on average level (6.4 - 6.8), which is recommended to prevent kidney stones.