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The regeneration (or recharge) cycle of a water softener is its most technical aspect. It’s also one of the most important steps as it ensures optimal performance and effective hard water treatment. While regeneration cycles can vary slightly between models, the principle and the stages are typically the same across models.
Here are the 5 stages of a water softener regeneration cycle.
Backwash
- The first stage of the regeneration cycle involves cleaning the resin bed of dirt, broken beads, debris and other contaminants that can clog the resin bed.
- Water flow is directed towards the bottom of the resin tank.
- The flow is then directed upwards through the resin bed, removing suspended solids and impurities. This cycle expands the resin bed up to 50% and prepares it for the next stage.
- The water then exits the tank from the top of the tank and into the drain, taking the contaminants and mineral compounds.
- This cycle takes about 10 minutes, at a flow rate of 4 – 8 GPM. The cycle must be regulated and should not allow resin loss.
Brine Draw
- Brine (salt water) is drawn from the brine tank and into the resin bed.
- The brine flows through the resin, triggering reverse ion exchange, as it exchanges sodium ions for hardness minerals.
- As this ion exchange process takes place, the resin bed is replenished with salt and removed of the accumulated minerals.
- The brine flow can be either upward or downward depending on the model of the water softener. However, brine upflow cycles, where the brine flows in the opposite direction to the service flow, are more efficient.
- This cycle takes about 30 minutes, at a flow rate of .05 to 1 GPM.
Slow Rinse
- Once the brine draw is complete, fresh water is directed into the resin bed to give the resin a rinse.
- This flow moves slowly, allowing the ion exchange process to be complete.
- It removes the brine and sends it towards the drain.
- This cycle takes about 20 minutes, at a flow rate of .5 to 1.0 GPM.
Fast Rinse
- Once the slow rinse cycle is complete, a fast rinse cycle commences, flowing quickly through the resin bed from top to bottom.
- This rinse removes any remaining brine and hardness compounds.
- It compacts the resin bed, preparing it for its service cycle.
- The cycle takes about 20 to 50 minutes, at a flow rate of 1.5 to 2.0 GPM.
Refill cycle
- In this last stage, water is directed towards and fills up the brine tank.
- By filling the brine tank with the required salt, you’re preparing it for the next brine draw cycle.
Some Important Considerations
The most efficient type of regeneration is demand-initiated, which initiates the cycle as per your water usage. Avoid timer- or schedule-initiated regeneration systems if you can, as these work according to a timer, regardless of your usage and thus are less efficient.
Also consider whether the water softener has a traditional downflow brining cycle (also known as co-current regeneration) or an upflow brining cycle (counter-current regeneration). Upflow cycles are more efficient and use significantly less salt and water.
To learn more about regeneration, check our detailed article here.
If you’re looking for the best water softeners, we recommend checking out our reviews and buying guide here.
