Caroma Toilet Cistern

[harm_less]

Water is over-flowing ..  a bit too high.  Need to bring it down a little. 
Simple reason.

We've had overflow problem in the past. It has occurred following plumbing work which has resulted in air getting to the pipes. That has caused sediment to be disturbed and bits of grit getting stuck in the valve system in the cistern. Running on after the cistern is full was the result.

We're rural and on tank water so if you're in a similar situation or have had plumbing work done recently maybe worth pulling the mechanism to bits and checking for debris.