For pools, ponds, aquariums, we use the Water Test meter to monitor 6 most important water properties in one unit  Useful for making colloidal silver and colloidal gold.  Use our colloidal silver generator to make your own colloidal silver


Conductivity is a measurement of dissolved charged entities. Conductivity is only a very approximate indication of ppm, because the nanoparticles have a negative charge which opposes the ion charge and confuses the measurement. Usually there is much more ppm present than conductivity would suggest.  Conductivity in microsiemens is a good approximate indicator of silver ppm, but not so useful for the other metals

Conductivity indirectly measures ions by measuring the passage of electrons through a sample of water. Solutions which have a lot of dissolved ions will have a high conductivity. Solutions which have a low concentration of dissolved ions will have a

low conductivity.   In addition, if you start with Reverse Osmosis water which has a conductivity of about 12 -20, you would have to subtract that value from the final measurement.

UltraMeter® 6P II Waterproof Water Quality Test Meter.  Measures Conductivity, TDS, Resistivity, pH, ORP & Temperature.

ORP (Oxidation Reduction Potential) measures the presence or lack of free electrons and is important in checking for presence of oxidisers such as Chlorine, Bromine, Ozone. An abundance of free electrons indicates an antioxidant benefit such as in Hunza Water.


  • Price includes calibration $1400 US
  • Click for Less expensive tester- PWT
    Our colloidal generators and swimming pool ionizers are Made in Canada and are ecofriendly, nonpolluting, nontoxic, noninvasive and designed to be preventive.
    Biophysica's colloidal generators, water purifiers, water descalers, and ionizers for swimming pools do not involve the use of chemicals, thus there is no damage to the environment. Also because our products are all manufactured in Canada, and when local Canadians purchase our products, there is much less pollution generated than when consumers import goods from overseas, plus our customers are not supporting child labour or unethical business practices when they buy from us.
  • Water Test  provides quick and reliable measurement of the four most important variables in water analysis, that is, pH, ORP (Oxidation-Reduction Potential), conductivity (0 to 1999 uS), and temperature. The lightweight and compact package makes it perfect for use in the plant as well as the field.  It will allow monitoring of ideal electrical conductivity (1000 microSiemens) necessary for proper functioning of water ionizers which charge the water with copper and silver atoms from electrodes.  

    Water Test is engineered with such simplicity that even non-technical personnel can use it. Fill the base of Water Test with the sample to be measured, press "RANGE" to select the mode and then simply read your measurement. 

    Superior in design and construction, the Water Test is made of rugged material which provides excellent protection from the typical conditions of the field and plant. When Hanna engineered the Water Test, they made it simple to use for even non-technical personnel. After the pH and conductivity calibration has been performed, measurements are simple. Fill the base of the Water Test unit with the sample to be measured. Turn the unit on and switch it to the desired range. Then simply read your measurement.

    The rugged construction and simple operation make Water Test perfect for use in the fields of water treatment analysis, waste water tests, ecological studies, aquaculture and hydroponic applications.
  • 4 instruments in 1 
  • Long battery life making the unit excellent for field operations 
  • Excellent accuracy across all ranges 
  • Lightweight and highly portable 
  • Obtain consistent accuracy through 3 calibration trimmers 
  • Easy to operate and maintain 
  • is an ideal instrument for water testing in lakes and rivers as well as swimming pools, aquariums and plating baths.
  • ability to test 4 different environmental parameters using just one simple meter.


The design of the Water-Test meter is such that it can be lowered into the water to be tested in order to fill the Black sample chamber at the bottom of the unit. It can then be removed from the water and stood in a position to allow for ease of reading of the various parameters

Using a simple range select rubber button on the front of the meter allows the operator to choose whether to read conductivity, pH, ORP (also known as Redox) or temperature. 

All the sensors are located in the Black sampling chamber at the base of the unit, where they are protected from accidental damage. 

For Colloidal Nanocrystalline Waters use the UPWT (Ultra Pure Water Tester) meter which is more sensitive for low levels of ppm, such as when using distilled or R.O. water.

colloidal water tester
We have searched carefully and recommend the pocket size Ultra Pure Water Tester (UPWT) which measures low levels down to 0.1 microSiemens (uS) of conductivity with 0.1 microSiemens resolution and full scale up to 99.9 microSiemens. We recommend that you do not buy the wider range, less sensitive meters going up to 1000 microSiemens or a TDS (Total Dissolved Solid) meter (calibrated for Sodium Chloride). 

 Ultra Pure Water Test (UPWT) enables you to check the purity of your distilled or demineralized water in laboratory or industrial environments. Ultra Pure Water Tester (UPWT) is an ideal tester for Mega ohm checks. UPWT is ideally suited for fields where distilled, demineralized or pure water is used. UPWT is the first pure water tester to measure in 1/1000ths of micro-Siemens and provides on-the-spot and fast checks for minute traces of contamination in your water, assuring high quality of finished products in processes. These testers are housed in a durable case that provides excellent protection against harsh industrial environments. The casing also features a larger LCD than previous models and with a more ergonomic shape is easier to handle.




0.0 to 99.9 µS/cm



0.1 µS/cm



±2% F.S.



manual, 1 point

Temperature Compensation


automatic, 0 to 50°C (32 to 122°F)

Battery Type / Life


4 x 1.5V / approx. 250 hours of continuous use



0 to 50°C (32 to 122°F); RH max 95%



175 x 41 x 23 mm (6.9 x 1.6 x 0.9")



95 g (3.4 oz.)

This very useful conductivity meter can be ordered from us.

Price of UPWT pocket water tester:  $160 US.

We can supply calibration solution of conductivity 84 uS to check any conductivity meter for accuracy.

Some of our samples of 38 microSiemens measured to be 24 ppm of Silver, which is a ratio of 38/24 = 1.58 or 24/38 = 0.63 = approximately 2/3 of the conductivity reading.  Other samples of 26.7 uS was equivalent to 14.5 ppm = ratio of 0.54, while other experts have found ratio of 1.2 which may mean that their CS had large uncharged particles of silver contributing to the ppm measurement.

TDS meters are calibrated for Sodium Chloride salt

0.1 microSiemens corresponds to 0.04 ppm (parts per million) of Sodium Chloride salt.

1 microSiemens corresponds to 0.4 ppm of Sodium Chloride salt.

10 microSiemens corresponds to 4.3 ppm of Sodium Chloride salt.

99.9 microSiemens corresponds to 48 ppm of Sodium Chloride salt.

Conductivity is the reciprocal of resistance. 1 microSiemens of  conductivity corresponds to an electrical resistance of 1 megohm, 100 microSiemens of  conductivity corresponds to an electrical resistance of 10,000 (10K) ohms, 

Understanding mS, g/l, mg/l, ppm, ppt & converting from one to the other

Electrical conductivity is the ability of a solution to conduct an electric current. It can be used as an index of the total solids (TDS) in a water sample.

The unit of measure commonly used in Siemens per centimeter (S/cm). The conductivity of water is usually expressed as microSiemens/cm (µS/cm) which is 10-6 S/CM. The relation between conductivity and dissolved solids is approximately:

2 µS/cm = 1 ppm (which is the same as 1 mg/l)

The conductivity of water from various sources is

Absolute pure water - 0.055 µS/cm
Distilled water - 0.5 µS/cm
Mountain water - 1.0 µS/cm
Most drinking water sources - 500 to 800 µS/cm
Sea water - 56 mS/cm (56000 µS/cm)
Max for potable water - 1055 µS/cm

Some common conductivity conversion factors are

mS/cm x 1 000 = µS/cm
µS/cm x 0.001 = mS/cm
µS/cm x 1 = µmhos/cm
µS/cm x 0.5 = mg/l of TDS
mS/cm x 0.5 = g/l of TDS
mg/l TDS x 0.001 = g/l of TDS
mg/l TDS x 0.05842 = gpg TDS

 Be aware that the above figures are for Sodium Chloride salt and do not correspond accurately to colloidal parts per million. This is because colloidal waters have positive as well as negative nanometre particles and ions, exerting complex double-layer, Zeta potential and quantum effects.  The only accurate method to measure colloidal waters is to do what we had to do and send a sample to a laboratory. 

Conductance in a solution actually involves the movement of ions.  Solutions of dissolved ions (dissolved salts) in water will pass the electric potential of a battery through them and allow the light bulb to light. A solution which will conduct a current is called an “electrolyte.”

Positively-charged ions are called “cations”, negatively-charged ions are called “anions.” Cations are formed when one or more electrons are lost from an atom or group of atoms, anions are formed when one or more electrons are gained by an atom or group of atoms. An electrolyte contains cations and anions. The more cations and anions present, the higher the conductivity.

If the amount of current passing through a solution is measured with a conductivity meter, we can tell relatively how many ions are dissolved in the solution. When more current passes through the solution, we know more ions are present.

Conductivity in a solution decreases as temperature decreases, whereas the conductance of a solid conductor (such as a copper wire) increases with decreasing temperature. Conductance in a solution is different than in a solid. Conductivity in a solution

actually occurs as a result of positive and negative ions moving through the solution. The cations are attracted to the negative electrode and migrate to it. The anions are attracted to the positive electrodeand migrate to it. Once a negative chloride ion reaches the positive pole, it donates an electron, and once a positive sodium ion reaches the negative pole it gains an electron. The transferred electron passes through the ammeter and registers as current (conductivity).

It is important to note that conductivity does not tell us what type of ions are present. Conductivity is only a relative measurement of the total number of ions present. Also, some ions exhibit a higher conductivity than others because they are more mobile. Hydrogen ions are the most conductive ions. Hydroxide ions are the next most conductive. All other ions fall below these two as far as

conductivity is concerned.

Pure water will exhibit some, although very little, conductivity. This is due to the fact that water will ionize each of the hydrogen ion and hydroxide ions very slightly.

Since typical potable water contains hardness, (calcium & magnesium) it is advisable, with very hard water, to soften the water that is being used to make the solution feeding the system. If feed water is not softened, scaling of the electrodes may occur as a result of a change in pH within the electrochemical process. Scaling will coat the electrodes, diminish electrical current flow and negatively impact the efficiency of the system.  We sell electronic water softeners and descalers which do not use chemicals.


Contact:  Biophysica Inc.,
Our Technical Support Hotline, Phone: 647-478-6946 or Toll Free 1-800-488-2032 from Canada, US and Territories (10am to 10pm Eastern Standard (New York) Time)
e-mail: biophysica at gmail dot com with copy to info at biophysica dot com
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This site  was last updated on July 22, 2013