When your RO starts to give you water which tastes salty, there are a couple of things which need to be looked into:
1) When was the last time the RO membrane was changed ?
Typically its recommended that the RO membrane installed be changed once every year. Of course this time period can vary depending on the TDS value of the raw water. If the TDS is low (<400), the membrane may last more than a year and in some cases when the TDS is very high (>1000) it may pack up in about 10 months. Nevertheless, the membrane is the most common reason for the water to taste salty. Get the membrane changed.
2) Post Carbon Needs To Be Changed
A post carbon module is typically added in between the pure water coming from the membrane and the tap. The post carbon element absorbs gases and organic material which otherwise changes the taste of the water. It also absorbs any trace chemicals which may have escaped trapping in the RO membrane. Sometimes when this module has not been changed for a while, the water may taste strange. If its been over a year, better change this module too, just to be safe.
3) The TDS Controller Needs To Be Toned Down
When the TDS controller is allowing excessive mixing of the water coming from the membrane and the UV tube, the water may taste strange. A quick way of coming to know if this is the cause, is to dial down the TDS controller to allow less water to flow through the UV tube. This will increase the water coming from the RO membrane and will lower the overall TDS value.
Questions Regarding Reverse Osmosis Systems 
The Kent RO water purifier, model: super star. The machine shows power is ON (green light) and normal sound of pump running. But water is not coming through waste water line.
Requesting guidance to further check and solution.
I used 4 ton r.o machine which is 40 80. The first 2 taste good water but the last 2 taste like raw water why
Fungicide for Reverse Osmosis Film Components (UN-611)
Product Description:
UN—611 is a safe and effective non-oxidative fungicide with broad spectrum. It won’t cause hidden troubles like bromine, iodine, peroxide and other drugs on the reverse osmosis film system . Instead, it can effectively inhibit microorganism from growing and attaching to the reverse osmosis film system, so as to reduce the pollution and prolong the service life of the reverse osmosis membrane.
Due to the unique chemical properties of UN—611, small dosage in use can take the bactericidal effect with great rapidity, it is particularly suitable for Fungicide for Reverse Osmosis systems that are plagued by biological contamination, can be used to control the whole process of the breeding of microbes in the reverse osmosis system.
Especially for the reverse osmosis systems that are plagued by biological contamination.
I changed the New RO osmosis filter New and the water still taste salty
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