question: Why does water that sits out too long taste “stale”?
comment: Carbon dioxide from the air mixes with the water, lowering the Ph and making it taste different.
passages: BULLET::::- Maximum Nitrogen Concentration (NH4-N [micro l-1] of 13 on the surface and 120 at the bottom of the lake have been reported.
  
  BULLET::::- The lake water temperature varied from a minimum of in January to in June/July at the surface and correspondingly and , at the bottom of the lake.
  
  Section::::Water quality issues.:Flora.
  
  Within the lake water, the flora recorded comprise the following.
   Section::::Hard Water becomes Soft Water.
   BULLET::::- The lake is Monomictic Mixing type and develops thermal stratification in March to November. Maximum depth of the Thermocline is . Hypolimnion temperature ranges from to .
  
  BULLET::::- pH value varied from a maximum of 8.8 on the surface to a minimum of 7.7 at depth in year over the 12 months period
  
  BULLET::::- DO [mg l-1] value varied from a maximum of 10.4 on the surface to a minimum of 2.2 at the bottom in year over the 12 months period
   Some plants prefer flowing water, while others, such as lotuses, prefer stagnant water.
  
  Various anaerobic bacteria are commonly found in stagnant water . For this reason, pools of stagnant water have historically been used in processing hemp and some other fiber crops, as well as linden bark used for making bast shoes. Several weeks of soaking makes bast fibers easily separable due to bacterial and fermentative processes known as retting.
  
  BULLET::::- Denitrifying bacteria
  
  BULLET::::- Leptospira
  
  BULLET::::- Purple bacteria (both sulfur and non-sulfur)
  
  Section::::Life that may thrive in stagnant water.:Fish.
  
  BULLET::::- Lepisosteidae (gar)
  
  BULLET::::- Northern snakehead fish
  
  BULLET::::- Pygmy gourami
   BULLET::::- The lake water temperature varies from a minimum of in January to in June at the surface, and correspondingly at the bottom of the lake.
   As a consequence, the water level in the Metolius River is relatively constant. The rate of flow at the headwaters is approximately or 50,000 gallons per minute), although it grows by an additional or 600,000 gallons per minute) by the time the river reaches Lake Billy Chinook. Similarly, the water temperature is also stable; at the river source, the water temperature is a consistent .
  
  Section::::General.
   BULLET::::- Flow rate of air: This is in part related to the concentration points above. If "fresh" air (i.e., air which is neither already saturated with the substance nor with other substances) is moving over the substance all the time, then the concentration of the substance in the air is less likely to go up with time, thus encouraging faster evaporation. This is the result of the boundary layer at the evaporation surface decreasing with flow velocity, decreasing the diffusion distance in the stagnant layer.
  
  BULLET::::- The amount of minerals dissolved in the liquid
   Section::::Ecosystem.:Elevated mercury levels.
   Food designers use water activity to formulate shelf-stable food. If a product is kept below a certain water activity, then mold growth is inhibited. This results in a longer shelf life.
  
  Water activity values can also help limit moisture migration within a food product made with different ingredients. If raisins of a higher water activity are packaged with bran flakes of a lower water activity, the water from the raisins migrates to the bran flakes over time, making the raisins hard and the bran flakes soggy. Food formulators use water activity to predict how much moisture migration affects their product.
   The lake is stratified and seasonal mixing generally does not extend beyond depths of . The mixing mainly occurs as upwellings in the south and is wind-driven, but to a lesser extent, up- and downwellings also occur elsewhere in the lake. As a consequence of the stratification, the deep sections contain "fossil water". This also means it has no oxygen (it is anoxic) in the deeper parts, essentially limiting fish and other aerobic organisms to the upper part. Some geographical variations are seen in this limit, but it is typically at depths around in the northern part of the lake and in the south. The oxygen-devoid deepest sections contain high levels of toxic hydrogen sulphide and are essentially lifeless, except for bacteria.
   Section::::Water quality.
   Section::::Division of the riverine.:Lower reaches (Stream order 6).
  
  In the lower reaches, there is a large flux in particulate material and also a decrease in production through photosynthesis, due to an increase in water cloudiness (turbidity) and surface film from suspended FPOM. Here, like the headwaters, respiration outpaces photosynthesis, making the ratio again less than 1 (P: R 1). The living community in these areas are made up of almost exclusively collectors, as well as a small share of predators.
  
  Section::::Contributing factors.
   Purified water is also used in the commercial beverage industry as the primary ingredient of any given trademarked bottling formula, in order to maintain critical consistency of taste, clarity, and color. This guarantees the consumer complete reliability of safety and drinking-satisfaction of their favorite refreshment, no matter where in the world it has been bottled. In the process prior to filling and sealing, individual bottles are always rinsed with deionised water to remove any particles that could cause a change in taste.
   At long and wide, Lake George is long, largely flat and extremely shallow, with a very small catchment. Resultant evaporation rates as well as a tendency for strong winds to blow the water back on itself explain the mysterious filling and drying episodes on both short term (hours) and long term (years) time scales that have been observed.
   Pure water is usually described as tasteless and odorless, although humans have specific sensors that can feel the presence of water in their mouths, and frogs are known to be able to smell it. However, water from ordinary sources (including bottled mineral water) usually has many dissolved substances, that may give it varying tastes and odors. Humans and other animals have developed senses that enable them to evaluate the potability of water by avoiding water that is too salty or putrid.
  
  Section::::Chemical and physical properties.:Color and appearance.
   Moreover, concentration polarization leads to:
  
  BULLET::::- Increased salt leakage through the membrane
  
  BULLET::::- Increased probability of scale/fouling development
  
  Thus, the selectivity of separation and the membrane lifetime are deteriorated.
   Section::::Description.
  
  In the rainy winter season, high water levels enlarge the freshwater pond to more than . By spring, water levels begin dropping and by summer, the pond shrinks to half its winter size, leaving a salty residue behind: this accounts for its name, "Kealia", meaning "salt encrusted place"; Coastal salt pans once produced the mineral from seawater. The low water levels cause a 98% dieback in the tilapia population, which can produce a foul stench in the area.
   Lakes also receive waters, often from many different sources with varying qualities. Solids from stream inputs will typically settle near the mouth of the stream and depending on a variety of factors the incoming water may float over the surface of the lake, sink beneath the surface or rapidly mix with the lake water. All of these phenomena can skew the results of any environmental monitoring unless the process are well understood.
  
  Section::::Mixing zones.
   Solutes in water also affect water activity that affects many chemical reactions and the growth of microbes in food. Water activity can be described as a ratio of the vapor pressure of water in a solution to the vapor pressure of pure water. Solutes in water lower water activity—this is important to know because most bacterial growth ceases at low levels of water activity. Not only does microbial growth affect the safety of food, but also the preservation and shelf life of food.
   Section::::Kinder Downfall.
   BULLET::::- DO [mg/l] value varies from a maximum of 9.4 on the surface and minimum of 1.2 at the bottom, at 5 m depth the lowest value being 3.3.
  
  BULLET::::- Maximum Nitrogen Concentration (NO3-N [mg/L] ) of 0.941 at 1 m below the surface and 0.523 at the bottom of the lake have been reported.
  
  BULLET::::- The lake water is reported to be polymictic, and there is lack of true thermocline. Gradient is recorded to be poor, which results in frequent mixing, as experienced in many tropical lakes.
   Section::::Salinity.
  
  When the Suez Canal was closed for eight years, beginning during the Six-Day War the salinity of the lake increased substantially. The salinity of the lake depends on how much seawater flows into it from the Red Sea and the Mediterranean Sea. Even when the canal is open, the Great Bitter Lake has a salinity level "more than twice" the level of the sea, and while this does make it difficult for plant life to exist there, many species (of crabs, for example) do migrate from the Red Sea through the area.
   Section::::Chemistry.
  
  With 34.2% salinity (in 2011), it is one of the world's saltiest bodies of water, though Lake Vanda in Antarctica (35%), Lake Assal in Djibouti (34.8%), Lagoon Garabogazköl in the Caspian Sea (up to 35%) and some hypersaline ponds and lakes of the McMurdo Dry Valleys in Antarctica (such as Don Juan Pond (44%)) have reported higher salinities.
   Ramune is one of the modern symbols of summer in Japan and is widely consumed during warm festival days and nights. Empty bottles are usually collected for recycling at stalls where it is sold.
  
  Section::::Flavors.
   Tilapia is one of several commercially important aquaculture species (including trout, barramundi and channel catfish) susceptible to off flavors. These 'muddy' or 'musty' flavors are normally caused by geosmin and 2-methylisoborneol, organic products of ubiquitous cyanobacteria that are often present or bloom sporadically in water bodies and soil. These flavors are no indication of freshness or safety of the fish, but they make the product unattractive to consumers. Simple quality control procedures are known to be effective in ensuring the quality of fish entering the market.
  