Total Dissolved Solids?
1. "Dissolved solids" refer to any minerals, salts, metals, cations or anions dissolved in water. This includes anything present in water other than the pure water (H20) molecule and suspended solids. (Suspended solids are any particles/substances that are neither dissolved nor settled in the water, such as wood pulp.)
2. In general, the total dissolved solids concentration is the sum of the cations (positively charged) and anions (negatively charged) ions in the water.
3. Parts per Million (ppm) is the weight-to-weight ratio of any ion to water.
4. TDS is based on the electrical conductivity (EC) of water. Pure H20 has virtually zero conductivity. Conductivity is usually about 100 times the total cations or anions expressed as equivalents. TDS is calculated by converting the EC by a factor of 0.5 to 1.0 times the EC, depending upon the levels. Typically, the higher the level of EC, the higher the conversion factor to determine the TDS
Again, the same conductivity meter that measures TDS also measures salinity. It is the exact same measurement but expressed in either % or ppt (parts per thousand).
At 1% salt content, the TDS meter should read 10,000 ppm.
Say you put 0.3% salt in the pond to help with whatever. Well, that would be a TDS reading of 3000 ppm. It won't kill the fish!
This is a good way to measure salinity of your pond or q-tank.
