​An important aspect of any fermentation is monitoring, whether for pharmaceutical product, beer or biogas.
Biogas production is of course a 24/7 process ! Monitoring can be effective and return the cost within months. Just ask those who have had to restart their digester.
The tendency not to monitor can occur, but, we should recognise that we have an industrial process and fermentation environment largely dictates performance.
The long-term difference between good and poor digester performance is significant and could represent as much as a 20% loss meaning of course that 20% more feedstock may be required to achieve the target output!
​By effective monitoring we can identify issues early and make an informed decision as to how to recover the optimum methane producing microbial community. 

The most effective means of monitoring is the acid to base concentration ratio. Often described as the FOS/TAC ratio show below in traffic light coding. Monitoring can be performed with little cost and identifies over-loading and under-loading.
There are other parameters that we can help you with to fine tune performance of a healthy biogas forming microbial community.