Very pleased with this product. The wall fitting makes for a very easy filter change.
It worked for a few hours and produced about 100L before it stopped working. after sales support suggested that the RO element was blocked and to get a prefilter but the RO element was not blocked. It is missing critical components needed for it to operate once the RO element is fully saturated that can take a day. The RO input and concentrate ports are also connected backwards. There is a single 300cc flow limitter on the input of the RO element. RO needs about about a 1:5 ratio of permeate to concentrate for best performance. This would leave about 50cc of permeate flow but as the RO element is rated for 300cc/min of permeate flow not raw input -and by extension, 300ccx5=1500cc of concentrate flow, placing the 300cc limitter on the input leads to an initial drip followed by all the water exiting via the concentrate port and no permeate production. problem is that you also need a 350kpa/50psi pressure limiter, an adjustable flow limiter valve and probably an extra UF filter to protect the RO element and to throw away the included flow limiter or put it on the permeate port. put the adjustable limiter valve on the concentrate port. adjust the concentrate limit valve until you're happy with the flow ratio and tds of the permeate. Or just build your own unit from chinese parts. the same components for an 800gpd setup cost about the same as this kit. picture is what it should look like once you've fixed it and installed the critical components.
Hi Robert,
We normally don’t argue with customers in reviews unless there are factual or technical inaccuracies. I watched your video carefully, and there are several technical points I would like to clarify.
1. 350 kPa PLV
A 350 kPa PLV is not required for this system as long as the incoming water pressure is within the specified operating range.
The system can operate normally between 50–70 psi. Within the normal operating range, higher feed pressure can also improve RO membrane performance, including permeate flow and rejection.
This is also a portable system. Once it is disconnected from the water supply after use, it is no longer continuously pressurised. Therefore, there is no need to specifically limit the operating pressure to 350 kPa.
2. Ultrafine membrane
An ultrafine membrane is not required for the RO membrane to operate correctly.
UF membranes are mainly used to remove fine particles, colloids and microorganisms such as bacteria. Their flow rate is much higher than an RO membrane, but they do not remove dissolved minerals or reduce TDS in the same way as RO.
A much more important pre-treatment for a standard RO membrane is activated carbon. Chlorine in the feed water can oxidise and damage a polyamide RO membrane, which is why carbon filtration is included before the RO membrane in this system.
3. 300 mL flow restrictor
The system was supplied with a 300 mL/min flow restrictor installed on the concentrate/wastewater line. However, in your modified setup, this restrictor has been removed from the wastewater line and installed on the permeate/product-water line.
A standard RO flow restrictor is designed to be installed on the concentrate line. Its purpose is to restrict the concentrate flow and maintain the pressure required for the RO membrane to operate correctly. It is not intended to be installed on the permeate line.
The white adjustable valve shown on the wastewater line in your video is not a flow restrictor or a flow-control valve. It is an adjustable pressure-reducing valve (PRV).
A pressure-reducing valve regulates downstream pressure. It is not designed to control RO concentrate flow in the same way as a correctly sized flow restrictor.
4. Permeate-to-concentrate ratio
There is no universal requirement that an RO system must operate at a 1:5 permeate-to-concentrate ratio.
The appropriate ratio depends on several factors, including the membrane specification, feed-water quality, hardness, TDS, temperature and operating pressure.
Our system uses a 300 mL/min concentrate flow restrictor based on testing of this particular configuration. Under normal operating conditions, we have consistently achieved approximately 95% rejection, and the DI resin provides the final polishing required for the intended aquarium application.
Therefore, simply calculating that a 300 mL/min rated membrane must have 1,500 mL/min of concentrate flow is not a universal rule for RO systems.
5. Our previous troubleshooting
We previously suggested that the RO membrane may have been blocked because you advised us that the system initially worked and produced water, but later stopped producing water.
That was a troubleshooting suggestion based on the symptoms you described at the time. It was not a confirmed diagnosis that the RO membrane was definitely blocked.
6. RO inlet and concentrate connections
You also stated that the RO inlet and concentrate ports were connected backwards.
By the time your video was recorded, the original plumbing had been substantially modified, including relocating the supplied flow restrictor and adding additional valves and filtration components. It is therefore difficult for us to determine from the modified system how the original connections were configured.
We cannot say that an assembly error is impossible. However, these systems are produced in batches on an assembly line, with the same production step repeated across the batch. The tubing is also pre-cut to fixed lengths with very small tolerances. This makes this type of connection error unlikely.
This is a mature product that has been sold in the thousands. The basic configuration — sediment/carbon pre-filtration, RO membrane, concentrate flow restriction and DI polishing — is also widely used in aquarium RO/DI systems in Australia.
This response is not intended to argue with you or dismiss your experience. We simply want to clarify the technical facts so that other customers are not given incorrect information about how the system is designed to operate.
Still have not received the item which is paid in full for delivery.
28 days later.
May need to check your files if you think this has been "fulfilled".
No filter fit well come on time very happy thank you
Got two years supply in price of one. Great product and price.
