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.

UltraMeter® 6P II Waterproof Water Quality Test Meter for 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 PWT meter which is more sensitive for low levels of ppm.

colloidal water tester
We have searched carefully and recommend the pocket size Pure Water Tester (PWT) 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). 


Range   0.0 to 99.9 µS/cm
Resolution   0.1 µS/cm
Accuracy   ±2% F.S.
Calibration   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
Environment   0 to 50°C (32 to 122°F); RH max 95%
Dimensions   175 x 41 x 23 mm (6.9 x 1.6 x 0.9")
Weight   95 g (3.4 oz.)

This very useful conductivity meter can be ordered from us.

Price of 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.  They will do the following:

Ag -- Silver or Gold Concentration Analyses

The results of silver concentration analysis (in parts per million) and other pertinent observations will be returned with a Certificate of Analysis. Minimum 1 oz samples must be submitted, appropriately coded with your identification marks.

Particle Characterization Analyses

Observations are returned with a Certificate of Analysis and includes two b/w micrograph photos at 100,000x (unless otherwise specified). This analysis is designed specifically for imaging & sizing Silver particles.  Samples of a 10 ml minimum appropriately coded with your identification markings required. Work is performed on a  Transmission Electron Microscope (up to 480,000x magnification, resolution to 2.5 Angstroms).

Comparative Bacteriology Analyses

Samples are evaluated against various ‘standards’ for comparative bactericidal efficiency. Results are returned in a paper describing the methodology employed and images stripped from the culture plates.