## Method

Step 1 – Acid cleaning

- Start the Mexplorer with a citric acid solution of 0.5%, made with demineralised water.
- Measure the pH of the permeate and concentrate.
- Run the Mexplorer until the pH of the permeate and concentrate reaches 3
- Stop the Mexplorer and let the solution soak for 15 min
- Start the Mexplorer with tap/drinking water.
- Measure the pH of the permeate and concentrate.
- Run the Mexplorer until the pH of the permeate and concentrate is between pH 6 – 8.

Step 2 - Alkaline cleaning

- Start the Mexplorer with a caustic soda solution of 0.1%, made with demineralised water.
- Measure the pH of the permeate and concentrate.
- Run the Mexplorer until the pH of the permeate and concentrate reaches 11.
- Stop the Mexplorer and let the solution soak for 15 min.
- Start the Mexplorer with tap/drinking water.
- Measure the pH of the permeate and concentrate.
- Run the Mexplorer until the pH of the permeate and concentrate is between pH 6 – 8.

Step 3 - Acid cleaning

- Repeat step 1