Product information
Ecosoft BW MO6500 4″ reverse osmosis system for brackish water is a reliable and compact solution for treating water with a TDS of up to 10 000 ppm. Designed for demanding applications, it is built using corrosion-resistant AISI 316 stainless steel for all components in contact with feed water. The fully welded-free piping enhances resistance to high chloride content, allowing stable operation at pressures of up to 25 bar.
The system is equipped with the Ecosoft OC6000 controller, which offers online access and real-time monitoring of system performance, including flow rates, purified water quality, and operational status. Its compact design and compatibility with a standard 230 V power supply make installation and integration easy, even in space-constrained environments.
MO6500BI6 is an optimal choice for coastal installations such as private houses, cottages, and hotels. It is also suitable for small-scale industrial applications in the production of cosmetics, car care products, household chemicals, distillates, and laboratory water.
Reverse Osmosis Systems
Technical information
* The data are indicated under the operating conditions of the system at feed water temperature of 25 °C, a salinity of 7,500 ppm, Dupont LCLE4040 membrane element, the unit efficiency is 50%. The performance of your system may be different from these values depending on these factors, the chemical composition of the water and other factors. Use the RO calculator for your system.
* If the chloride content exceeds 2,000 mg/L, it may lead to a reduced service life of the pump due to corrosion. For detailed advice or water quality assessment, contact us at ecosoft@support.
To ensure maximum efficiency of the Ecosoft BW MO6500 reverse osmosis system, regular maintenance is essential. The system does not include a built-in mechanical pre-filter, so a separate 5 µm sediment filter must be installed before the reverse osmosis system.
We recommend using the following components:
- Ecosoft Big Blue 4.5″ × 20″ in-line filter housing
- Ecosoft PP melt-blown sediment filter, 4.5″ × 20″, 5 µm
Cartridge replacement schedule:
- Sediment filter – replace every 4 months or when the pressure drop reaches 0.5 bar
- Membrane element – replace or clean every 6 months, or if:
- productivity drops by more than 15–20%
- purified water quality worsens by 15–20%
- pressure drop increases by 15–20%
You can replace cartridges and membrane elements yourself, but for best results we recommend contacting an authorized service center.
If you decide to carry out the replacement yourself, follow the instructions below.
⚠️ Use sterile rubber gloves when handling membrane elements
⚠️ If high microbiological purity is required, disinfect the reverse osmosis system and the permeate tank before installing the membrane
Membrane holder cap
1 – Screws, 2 – Locking half-rings, 3 – End cap, 4 – Sealing ring, 5 – Sealing ring for the end cap.
Remove the membrane element(s) from the factory packaging. To replace the old element with a new one, disconnect the pipelines and remove the membrane holder(s) from the frame.
⚠️ Pay special attention to the sealing ring of the end cap (5). If the seal is missing, permeate and concentrate streams may mix.
After removing the end cap, install the membrane element in the direction of the arrow marked on the membrane holder (from the inlet water side). The membrane element must be inserted into the holder with its sealing ring aligned with the inlet connection of the holder head.
After installation, secure the holder head with screws and locking elements to the holder body, then reconnect the pipelines for feed water, concentrate discharge, and permeate outlet on the membrane holder. Fix the membrane holder to the reverse osmosis system frame.
During the first system startup, the initial portion of permeate must be discharged to the sewer, with a minimum discharge time of 15 minutes.
💡 When installing the membrane, pay attention to the direction of the arrow on the membrane holder.
💡 If necessary, use glycerin as a lubricant.
Consumables
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LCLE4040£ 710.00 excl. VAT£ 852.00 incl. VAT
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BW4040ES£ 499.17 excl. VAT£ 599.00 incl. VAT
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ELP4040£ 285.83 excl. VAT£ 343.00 incl. VAT
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CPV45205ECO£ 23.33 excl. VAT£ 28.00 incl. VAT
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FPV4520ECOGR£ 64.17 excl. VAT£ 77.00 incl. VAT
Local support
Our partners are happy to support you with their expertise, ensuring a Professional installation and Easy Maintenance.
Just leave a short note and we will connect you with one of our local partners!
FAQ
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Why might the MO6500BI6 be suitable for my application?
The MO6500BI6 is designed for brackish water treatment in applications where feed water contains elevated salt levels. The system is built with AISI 316 stainless steel components without welding, ensuring reliable long-term operation with feed water TDS of up to 10,000 ppm.
The OC6000 controller supports stable operation and continuous monitoring, helping maintain consistent water quality.
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What are the advantages of a brackish water reverse osmosis system?
Brackish water reverse osmosis systems offer several key advantages:
- suitable for feed water with TDS up to 10,000 ppm
- all wetted parts made of AISI 316 stainless steel for corrosion resistance
- Grundfos® CRN high-pressure pump designed for demanding conditions
- welded-free AISI 316 stainless steel piping
- operating pressure up to 25 bar for stable performance
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How can I calculate the capacity of the MO6500BI6 for my setup?
You can estimate the system performance using the graph provided in the Ecosoft Professional MO6500BI6 RO technical data sheet in the Downloads on this page (left sidebar).
To calculate the permeate flow rate at 15 °C and feed water TDS of 7,500 mg/L, refer to the chart below:
Ecosoft MO6500BI6 flow rate chart- On the FEED WATER TDS axis, mark the point corresponding to 7,500 mg/L (1).
- Draw a line to intersect the curve for 15 °C (2).
- From the point of intersection, draw a line toward the PERMEATE FLOW RATE axis (3).
The result is approximately 280 L/h.
To get the most accurate estimate, a complete feed water analysis is required.
If you already have this analysis and know the water temperature, feel free to send us the data. We will calculate the performance using specialized software such as Wave from DuPont or QPlus from LG. Contact us at [email protected] — we look forward to your requests.
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What water quality can I expect after filtration?
To determine the quality of water after the system, you can use software to calculate the operating parameters and expected purity.
Projection tools like Wave from DuPont and QPlus from LG allow for detailed modelling. You can also use the Ecosoft RO calculator to get an approximate estimate based on basic input data.
If you would like support with this, send your feed water parameters to [email protected] — we’ll be happy to help.
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What is the recovery rate of the MO6500BI6 system?
The recovery rate of brackish water reverse osmosis systems typically ranges from 40% to 60%. The exact value depends on the feed water quality, primarily its TDS level.
Lower feed water TDS allows for higher recovery. To estimate the recovery rate for your specific application, please send a water analysis to [email protected]..
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What minimum pre-treatment is required for brackish water reverse osmosis systems?
At a minimum, feed water must be treated to remove mechanical and suspended particles. Automatic backwash filters with Filter-Ag® or Filter-Ag Plus® media are commonly used for this purpose.
If organic contaminants are present, activated carbon filtration such as Filtrasorb® 300 can be applied. To reduce the risk of scale formation, the use of an antiscalant is recommended.
A typical pre-treatment setup for brackish water applications is shown in the illustration below.
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Which membrane elements are recommended for the MO6500BI6 system?
For brackish water applications, membrane elements designed for high salt content should be used.
For the MO6500BI6, commonly used options include:
The final choice depends on your feed water quality and the required permeate parameters. To estimate the expected water quality, please [email protected].
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What additional applications can brackish water reverse osmosis systems support?
Brackish water reverse osmosis systems can also be used to increase overall water efficiency at a facility.
For example, reverse osmosis concentrate can be further treated and reused, allowing total water efficiency to exceed 90%, depending on the system configuration. An example of such a solution is shown in the illustration below.
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Can brackish water reverse osmosis systems be used to achieve very low TDS?
Yes. Brackish water systems can be combined with highly selective membrane elements, such as LG BW 4040 ES or LG Chem’s BW 4040 R, to achieve very low TDS levels.
When mixed-bed ion exchange resins are used after brackish reverse osmosis, this approach can significantly extend their service life. Based on practical experience, the lifetime of mixed-bed resins can be increased by up to two times.
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Can brackish reverse osmosis remove nitrates and silicates?
Yes. Thanks to high operating pressure and the use of high-selectivity membranes, brackish reverse osmosis systems can achieve a high removal rate of nitrates and silicates.
To estimate the expected water quality for your specific source water, please send a water analysis to [email protected], and our specialists will provide an approximate calculation.
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From which seas or coastal wells can water be treated using brackish reverse osmosis?
Brackish reverse osmosis systems are suitable for treating water with salt content up to 10,000 mg/L.
In Europe, this includes water from low-salinity seas such as the Baltic Sea, Bothnian Bay, Gulf of Finland, Gulf of Riga, the northwestern Black Sea, and the Azov Sea, as well as coastal wells influenced by these seas. Such water sources can be treated to produce drinking water using brackish reverse osmosis technology.
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What are the advantages of the Grundfos pump used in brackish water systems?
The Grundfos pump used in this model offers several advantages:
- low energy consumption (1.5 kW)
- single-phase power supply (1 × 220–230 V)
- low noise level (55 dB)
- built-in dry-run protection
- high operating pressure (up to 25 bar)
- wetted parts made of AISI 316 stainless steel
- global manufacturer’s warranty from Grundfos
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Can I connect multiple tanks after the system?
Yes, it is possible to connect two or more tanks to a single system.
If you have such a need, contact us at [email protected], and we will recommend the best solution.
We also suggest considering a ready-made option for this purpose — the Ecosoft Smart Water Keeper 500 L water tank.
