RO water filter system - The original

I bought an under the sink RO water filter system over a year ago. The system cost about 2700 THB in Thailand which is around 75 USD. The price is pretty good when you know where to go. The price in the shopping malls and big water company could be anywhere around 5000 to 10000 (140 - 280 USD).

There were a few model to choose from. Without much knowledge of how the system works, I just went to the cheapest one and avoid the fancy electronic system with lot of flashing LED.

After about a day of drilling, piping and power cable connection I got it up and running. The TDS was about 10-12 on the first installation. My wife said the water taste much better than the water from our previous 3 stainless steel cylinder ceramic filter system.The system filter to 0.1 micron compare to 0.0001 micron of the RO system.

The RO system come with high/low pressure switch, booster pump and also auto flush valve. I thought the system was 50 GPD but only after I replaced the membrane with 50 GPD that I realized it is actually 75 GPD system.

Pictures of the installation and the schematic are below.

The system came equipped with auto flush flow restrictor, high and low pressure switch.
The high pressure switch cut the pump off when the tank is full and start the pump when the tank need top ups. The low pressure switch cut the pump off when there is not enough pressure on the inlet so the pump would not be starving. Auto flush valve with flush the membrane for a few seconds when the system start and then restrict the flow to build up pressure. This is pretty neat. Most of the systems out there got only flow restrictor and some with manual flush valve. 

After 4 months I decided to take the PP filter out and this is what I found:

It doesn't look too bad, especially on the inside: