When do I change my pool ionizer electrodes?

How do I know when it’s time to replace my mineral electrodes?

The ClearBlue mineral electrode will last one to three seasons depending on the size and usage of your pool or spa. In a pool, the first electrode will go quicker because the minerals need to ramp up in the water. Once they have ramped up, there are very stable, even over the winter. So, subsequent electrodes will last longer.
If the ‘Ionizing’ light on the ClearBlue is OFF, it’s time to replace your electrode:
Pool Ionizer Ionizing
If your electrode plates look like this, it’s almost time to replace it:
Almost spent pool ionizer electrode
This person waited a bit too long: