What is the TDS Index in a Reverse Osmosis System?

The high or low TDS value can visually reflect the performance of RO systems filtered water.
What is TDS?
TDS is the abbreviation of "Total Dissolved Solids," which refers to total dissolved solids measured in milligrams per liter. It indicates how many milligrams of dissolved solids are dissolved in 1 liter of water. So that means that the only dissolved solids that the TDS value can be measure are:
1 Dissolvable salts (calcium ions, magnesium ions, etc.)
2 Ionic organic matter (ammonium acetate, sodium sulfate, etc.)
3 Some heavy metal ions (chromium, zinc, lead, copper, etc.)
Why can the TDS value be used to determine the filtration effect of the RO system?
Note that the size of the TDS value does not directly represent the quality of water, but it can reflect the purity of water. By comparing the value of pure water and raw water, you can confirm the filtering effect of the water purifier. After the RO system filtered water, will undoubtedly be lower than the original water, as to how much lower, but also depends on the effect of the desalination rate of the RO membrane, which depends on the quality of the RO membrane.
It should be stressed that the TDS value to determine the effect of a water purifier only applies to a pure water machine and is not retrofitted with a mineral filter water machine. In addition, ultrafiltration machines, etc., are not applicable.
At this point, you may ask, drinking water with a low TDS value, that is, pure water, is good for our body?

The answer is yes.
1 The high solubility of pure water is very easy to be absorbed by human cells, which helps to promote metabolism
2 Pure water is a weak alkaline beverage that can eliminate grease from the human system
3 Ironing clothes with pure water, boiling water is more free from the trap of scaling
4 Washing the face with pure water regularly can moisturize the skin, prevent facial wrinkles, and play a beautiful effect
5 Use pure water to cook food, make tea, cook, taste better
On the other hand, drinking pure water for a long time may lack the necessary minerals, but don't worry, you can get all these substances from your daily diet.
Why is the TDS value still high after filtration?
The following are a few ways to test the TDS value.
a.First, need to test the raw water TDS value, RO membrane desalination rate of 96% or so
b.The raw water TDS value is too high
c.If the calculated RO membrane desalination rate is less than 90%, the measurement should consider internal leakage. It can be processed as follows: remove the RO membrane, there are two small waterproof rubber rings on the left side of the RO membrane, you can wrap the appropriate amount of raw tape in the two small rubber rings, and then install on the measurement.
d.  If the new replacement of the reverse osmosis membrane, you need to run 20 such as the recent replacement of the post-activated carbon also need to be flushed
e.  Confirm whether the pure water in the storage bucket is stored for too long 
f.  The pure water port of the RO membrane shell has no cracks, which may cause the mixing of pure water and wastewater
g.  Measurement of pure water quality, please measure from the reverse osmosis membrane pure water port 9, high-pressure pump pressure is not enough
h.  The pre-filter is not regularly replaced
The TDS value is too high for a reason, the quality of the RO membrane itself may have problems. The water purification industry has developed so far, and some irregular manufacturers make fake products, so be sure to buy regular brands. For example, YUNDA water purification has 21 years of experience in the industry, all certificates are available, thoroughly professional, you can log on to the website to view them: /water-filter-cartridges/water-filters-for-kitchen-bathroom/ro-system/
I hope this article can be of help to you.