TDS Creep

The 'TDS Creep' phenomenon, a significant challenge in Reverse Osmosis systems, is primarily caused by the membrane and Remineralisers.

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When a Reverse Osmosis (RO) system is not in operation (when the storage tank is full), the semipermeable membrane experiences natural 'Osmosis' due to the absence of pressure being applied. This results in a temporary spike in the Total Dissolved Solids (TDS) output when the system resumes water production. A membrane 'Flush' procedure is commonly employed to mitigate this issue. Modit has revolutionised this by incorporating an innovative flush system controlled via an adjustable timer. TDS creep is completely eliminated by setting the timer to a maximum of 30 seconds while conserving 80% less water than traditional flushing methods. This forefront solution offers unparalleled efficiency and flexibility in TDS output management.

It must be noted that systems without a membrane flush function (unpowered systems) will accumulate increasing TDS levels in the storage tank over time, negating any claimed membrane rejection percentage, and higher TDS rejection rates require higher P:B ratios.

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Remineralisers serve as sacrificial devices to infuse water with minerals, such as calcium and magnesium. The water's mineral dissolution level is determined by water contact time. During periods when the system is inactive, the extended contact time allows higher quantities of minerals to dissolve into the water, consequently increasing the TDS and altering parameters. However, unlike the membrane creep phenomenon, the short burst of altered water upon system activation from the remineraliser is viewed favourably due to its beneficial attributes. Therefore, no specific actions are taken to rectify this phenomenon, as its effects are considered advantageous.