1. Introducció
This manual provides essential instructions for the installation, operation, and maintenance of your Gre GOSA25 One Salt Salt Electrolyzer. This device is designed to efficiently treat pool water up to 25 m³ by generating chlorine from salt, ensuring clean and hygienic water with minimal effort. Please read this manual thoroughly before installation and use to ensure safe and optimal performance.

Figure 1: Gre GOSA25 One Salt Salt Electrolyzer. This image shows the electrolyzer unit positioned next to a swimming pool, illustrating its typical operational environment.
2. Informació de seguretat
Instruccions importants de seguretat:
- Always disconnect the power supply before performing any installation, maintenance, or service on the unit.
- Ensure the electrical installation complies with local regulations and standards.
- Do not operate the electrolyzer if any part is damaged or if the power cord is frayed.
- Mantingueu els nens allunyats de la unitat durant el funcionament i el manteniment.
- Maintain proper salt levels as indicated by the device to prevent damage and ensure effective operation.
- Consult a qualified electrician for any electrical work.
3. Configuració i instal·lació
The Gre GOSA25 electrolyzer is designed for easy integration into your pool's filtration system. Proper installation is crucial for optimal performance and safety.
3.1. Instal·lació elèctrica
The unit can be connected in two ways:
- Option 1: Simultaneous Connection: Connect the electrolyzer and the pool pump to the same power source, allowing them to operate concurrently.
- Option 2: External Timer: Connect the electrolyzer to an external timer, which can control its operation independently or in conjunction with the pump. The unit contains an internal timer for auto mode, but an external timer can override this.

Figure 2: Recommended Electrical Installation. This diagram illustrates two options for connecting the electrolyzer to the power supply, either simultaneously with the pump or via an external timer.
3.2. Connexió hidràulica
The electrolyzer cell must be installed in the return line of your pool's filtration system, after the filter and heater (if applicable), and before the water returns to the pool. Ensure the flow direction matches the arrows on the unit.
- Compatibilitat: The unit is compatible with rigid DN50 pipes and flexible hoses with a diameter of 32-38mm.
- Cell Connection: Securely connect the cell to the plumbing using appropriate fittings. Ensure all connections are watertight to prevent leaks.

Figure 3: Cell Connection Options. This image displays diagrams for connecting the electrolyzer cell to both above-ground and in-ground pool plumbing systems, detailing the necessary fittings.
4. Instruccions de funcionament
The Gre GOSA25 features a 4-digit LCD display and control panel for easy monitoring and adjustment of operating parameters.
4.1. Tauler de control acabatview

Figura 4: Tauler de control. Aquesta imatge en mostra un primer pla view of the electrolyzer's control panel, showing the LCD display, menu buttons, and indicator lights for various functions and alarms.
The LCD display shows important parameters such as:
- Salinitat: Current salt content in the pool water.
- Temperatura: Temperatura de l'aigua.
- Mida de la piscina: Configured pool volume.
- Safety Alarms: Indicators for various operational issues.
4.2. Initial Setup and Salt Addition
Before starting, ensure the pool volume is correctly set in the system. The electrolyzer will indicate the exact amount of salt (in kg) required if the salt content is too low. Add salt directly to the pool water, allowing it to dissolve completely before operating the unit.
4.3. Modes de funcionament
- Mode normal: For daily, continuous chlorine production to maintain water quality.
- Mode boost: Provides intensive chlorine production for periods of heavy use, high temperatures, or when extra sanitization is needed.
Use the control panel buttons to navigate through menus and select the desired operating mode.
5. Manteniment
The Gre GOSA25 is designed for minimal maintenance, primarily due to its self-cleaning cell.
5.1. Cell Cleaning
The transparent cell features an automatic self-cleaning system through polarity reversal, which occurs approximately every 8 hours. This process helps prevent scale buildup on the electrodes, ensuring consistent performance and extending the cell's lifespan up to 7,000 operating hours.
While automatic cleaning is effective, periodic visual inspection of the cell is recommended. If excessive scale buildup is observed, manual cleaning may be necessary. Consult the full product manual for detailed manual cleaning procedures.
5.2. Salt Level Monitoring
Regularly monitor the salt level displayed on the LCD. Maintain the optimal salt concentration as recommended by the manufacturer to ensure efficient chlorine production and prevent damage to the cell.
6. Solució De Problemes
This section addresses common issues you might encounter with your Gre GOSA25 electrolyzer.
| Problema | Causa possible | Solució |
|---|---|---|
| "Low Salt" Alarm | Insufficient salt concentration in the pool water. | Check the LCD display for the recommended amount of salt (in kg) to add. Add the specified amount of pool salt and allow it to dissolve. |
| "High Salt" Alarm | Excessive salt concentration in the pool water. | Partially drain the pool and refill with fresh water to dilute the salt concentration. |
| No Chlorine Production | Low salt level, power supply issue, flow sensor not detecting water, or dirty cell. |
|
| Missatge d'error a la pantalla | Indicates a specific operational fault (e.g., flow sensor, temperature sensor). | Note the error code and refer to the comprehensive product manual or contact customer support for specific guidance. Ensure flow and temperature sensors are clear and functioning. |
7. Especificacions
| Característica | Detall |
|---|---|
| Nom del model | GOSA25 |
| Marca | Gre |
| Producció de clor | 4 g/h |
| Volum de piscina recomanat | Up to 25 m³ (at 25-28 °C water temperature) |
| Cell Lifespan | Up to 7,000 operating hours |
| Sistema d'autoneteja | Automatic polarity reversal (up to every 8 hours) |
| Mostra | 4-digit LCD (salinity, temperature, pool size, alarms) |
| Modes de funcionament | Normal, Boost |
| Hydraulic Compatibility | Rigid DN50 pipes, flexible hoses 32-38mm diameter |
| Dimensions del producte (L x A x A) | 17 L x 34.3 W x 17 H centímetres |
Nota: les especificacions estan subjectes a canvis sense previ avís.
8. Garantia i Suport
For warranty information, please refer to the documentation provided with your purchase or contact your retailer. The warranty period and terms may vary depending on your region and point of purchase.
For technical support, troubleshooting assistance beyond this manual, or spare parts, please contact Gre customer service or your authorized dealer. Keep your purchase receipt and product model number (GOSA25) readily available when seeking support.