"Mary Fisher" wrote in message
"FarmI" ask@itshall be given wrote in message
...
"Sacha" wrote in message
"Charlie Pridham" wrote:

Most people I know with modern ones have a yearly contract.

I think there might be quite a lot in that last sentence, Charlie. I'm
a
bit concerned that the OP is hearing about people who haven't touched a
tank
in 15 years

If it's working and not causing any problems why should it be interfered
with?

Those who have such working installations are confident that they don't
need interference for any reason.

Mary

Incorrect attribution Mary.