TDS: Total Dissolved Solids (TDS) are the total amount of mobile charged ions, including minerals, salts or metals dissolved in a given volume of water, expressed in units of mg per unit volume of water (mg/L), also referred to as parts per million (ppm). TDS is directly related to the purity and quality of water and water purification systems and affects everything that consumes, lives in, or uses water, whether organic or inorganic.
PPM:Parts per million (PPM) is a way of expressing percent (%) in small amounts. In hydroponics, it is used to express the quantity of one amount of material dissolved into another (salts into a volume of water). Most plants do well between 1000 and 2000 PPM (0.1% to 0.2 % of dissolved salts). 1 tsp. of Ecogrow is approximately 600 PPM. 2 tsp. is 1200 PPM and 3 is 1800 PPM. The PPM is therefore controlled by the amount of dissolved salts used. PPM is measured electronically on meters. In Europe, the Siemen or E.C. is used I E.C. or 1 Siemen = 1 mho/cm of conductivity. To convert E.C. or Siemen to PPM, multiply them by 650. The Mho is the reciprocal of the Ohm of electrical resistance.
Technical data (PPM, pH and element concentrations) are listed on the technical data sheets for all Eco products.
No, plain tap water will have a ppm of about 250.
If the 40 gallon and 5 gallon are all the same water, they will both have the same ppm.
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