BioDiesel rabbit fuel tank replace?

I have a '79 diesel rabbit with '81 engine, bought couple months ago, just started using biodiesel fuel, 1st time this tank has seen it since inception, wondering if smart to replace fuel tank entirely so no gunk gets beyond fuel filter, would this be ideal or overkill, would rather not replace & just change filter often, but don’t want gunk getting discharged by solvent biodiesel beyond fuel filter, to injectors perhaps, is this a threat or can i relax & not do anything other than simply change fuel filter often, or do i actually need to replace fuel tank, cheaper than getting cleaned, thanks!

Are talking about real bio-diesel fuel? Or used cooking oil?

Tester

It’s hard for any of us to speculate as to if and how much your tank may be contaminated. Use your judgement based on what you know of the vehicle’s history.

Why on earth would it cost more to clean this one than to get another tank ?