Plastic mash tun getting stained

[Lunkerking]

After about a year of use my plastic cooler mash tun has developed some brown stain due to the mash. I clean it right after by rinsing it off and use some pbw as well. Are these stains pretty normal and are they anything to worry about ?

Thanks.

 

[EcuPirate07]

Shouldn't be an issue, my hop buckets became stained overtime. Just part of it.

 

[Cyclman]

Plastic is more porous than people realize.

 

[Gavin C]

Plastic is more porous than people realize.

Peoples' perception of plastics' porosity may be more profound than your own realization.

 

[Clef051]

Mine is stained, i don't worry about it