TDS and pH Testing Procedure for Full Contact® Artesian Systems
TDS Testing-
In order to obtain a good understanding of the system performance it is important to sample the TDS at three points in the system - the feed water, the product water from the RO membrane before remineralization, and the final product water. In this manner you will know the starting TDS before purification, the TDS removal rate and the amount of minerals added. Please note that Full Contact® Artesian systems add minerals to the water in order to increase the pH. These minerals (calcium 95% and magnesium 5%) will contribute to a TDS reading.
The amount of TDS from calcium and magnesium minerals added by the Artesian and Artesian Full Contact remineralization system will vary according to a number of factors, including the life cycle of the Artesian filter. It will also vary according to contact time, so when testing the TDS of an Artesian system it’s important to replicate normal usage. The Home Master RO system will reduce the feed water TDS by 98% and add 30-60 ppm (Artesian Full Contact) under the following specific conditions: 250 ppm NaCl TDS, 77PSI, 70F, and 7.5pH. Water with low starting TDS or pH may not achieve the full remineralization levels. Your results may vary - based upon your water’s composition, temperature, pressure, pH and filter life.
Tools:
Clean sample cups
TDS meter
1. Measure TDS from Kitchen Faucet: Draw water from kitchen faucet (Point A) into a clean sample cup. Measure the TDS and write down the result.
2. Measure TDS from RO Faucet: Draw water from RO faucet (Point C) into a clean sample cup. Measure the TDS and write down the result. For best results take the first few oz of water after the system has stood without use. Drawing out more than a quart of water will not represent normal use and will not product accurate, comparative results.
3. Close water valve feeding the system.
4. Close reserve tank valve.
5. Open RO faucet to relieve system pressure, leave open.
6a. Systems with Permeate Pump: On the permeate pump, locate the line coming out of the port labeled “permeate out”. Trace that line to the automatic shut off valve (or the termination point of the tubing) and remove the tubing from this port. Point the tube into a large bowl and turn the water to the system on. Allow the water to flow for a few moments, and then point the tube into a clean sample cup for testing. Test the water in the sample cup with the TDS meter. Repeat until a stable consistent result is obtained. Write down the result - (Point B).
6b. Systems without Permeate Pump: Locate the white elbow fitting at the bottom of the blue membrane housing in the center of the filter cluster. Trace the tubing from this white elbow to where it connects to the automatic shut off valve (a silver and white disk) and remove the tubing from this port. Turn the elbow with its tubing so that it points downward. Point the tube into a large bowl and turn the water to the system on. Allow the water to flow for a few moments, and then point the tube into a clean sample cup for testing. Test the water in the sample cup with the TDS meter. Repeat until a stable consistent result is obtained. Write down the result - (Point B).
7. Pressurize the Home Master® RO - Make sure unit is dry. Double check to make sure all valves are in the closed position, except for the main angle-stop valve, which should be open. Water should flow normally from your kitchen faucet. SLOWLY open the EZ adapter ball valve. You should hear water rushing through the system. Open the RO faucet to by flipping the lever up, where it should stay open. A trickle of water should be present after a few minutes. Close the lever on the RO faucet after the trickle runs clear, and allow the system to pressurize.
When the system has pressurized and shuts off automatically; (IMPORTANT STEP) dry unit thoroughly, gently tug on each connection and check for leaks. Then open the reserve tank valve slowly. Allow reserve tank to fill for 2.5 hours or until full.
Testing Complete.
Interpreting TDS Results:
The difference between points A and B will indicate the general health and effectiveness of your reverse osmosis membrane, and the reverse osmosis removal rate.
The difference between points B and C will indicate the general health and effectiveness of your Artesian filter, and the remineralization rate.
pH Testing-
In order to obtain an accurate pH reading you will need to use a good digital pH meter to test the water’s pH. Please do not use test strips or pH paper, for pH testing RO water. Test strips can be off by a full point or more when testing RO water because the water is so pure and light. They are notoriously inaccurate for pH testing even on higher TDS municipal water. City water will always measure an alkaline pH. Municipalities will not allow an acidic water to flow through the infrastructure as this will result in accelerated erosion, leaching of metals, costly repairs, leaks and lots of lawsuits (as we saw in Flint, Michigan).
Water has a limited ability to buffer against changes in pH so a small amount of something very acidic or very basic will have a large impact on the solution’s pH. This can very easily understood when you think about adding a few drops of lemon juice to a large glass of tap water and immediately detecting the change in taste – sour – which is how the tongue registers acidity. Its TDS will barely change but its pH will change substantially because of the lemon juice’s very low pH and water’s very limited ability to buffer against changes in pH. Water can even become acidified from the CO2 in the air, if the water is left to stand, and is one reason why we don't recommend our customers store jugs of drinking water in the fridge.
Two Ways to Test Water pH
While the best way to test the pH is with a lab test, or a digital pH meter, an alternative method is testing for a surrogate indicator, such as TDS. You may use a TDS meter to see that the system is working correctly. Test the water as it leaves the RO membrane, and at the RO faucet, and then compare those readings to the tap water. Remember, the Home Master Artesian RO systems add calcium and magnesium minerals to increase the pH, and these pH increasing minerals show up in a TDS reading (please see the section above for comprehensive testing procedures).
Further Reading: