Many thanks for the warning. I did remove the potmeter when I set up the kit 7 years ago - just forgotten I had. I also ordered and received 10 ldrs via Amazon which seem to do the job really well, so many thanks for your help and advice
Many thanks for your response. The threshold for the kit working effectively is under 300 Ohms. Today is cloudy and registering 328 so I guess it would be worth me trying the 2 silonex ldrs. The kit has an adjusting screw and I also added a potentiometer so I think I have quite a bit of leeway...
Let me preface this by saying I know almost nothing about electronics. As a result I purchased a Cebek I-104 light detector relay module which for a number of years has allowed me to boil up a hot water urn when the sun is shining (but clouds interrupting) and my solar panels are sending power...