Heating oil tank (plastic) has rusty coloured layer on bottom...

[Plumb Line]

Hi

The tank is around 7 years old. Any ideas what causes it and/or whether it is a problem?

Sorry the photo is not great, it's the best I can get through the small opening.

Many thanks

 

[ShaunCorbs]

It’s silt / sludge ideally need to run the oil low and clean the tank speak to your oil supply they might be able to do this for you