Saltwater mixing tank crud

[butesch]

How do you remove the tough crud in your saltwater mixing container. I’m not talking about calcium precipitate. This is dark brown stuff. Power washer would not remove it which surprised me. Do you think some muriatic acid would work if I let it sit over nite? Please give your thoughts.

 

[NDFoz]

White Vinager?

 

[butesch]

White Vinager?

Tried vinegar. Nothing happened.

 

[Schulks]

I haven't looked in my mixing bin for ages..
I think last time I just took a paint scraper to it.

 

[NDFoz]

Tried vinegar. Nothing happened.

How about that citric acid stuff they use to clean pumps and gyres? Put some in a bucket with water and scrub the heck out of it?