We bought a yacht with bladders and have never had a problem with the taste because we use filters - inline both before it goes in to the tanks
and right at the galley
sink. Where possible we also fill from rainwater or spring water, as the chlorine (and other additives) in town water taste disgusting to people used to living off the land. Having said that, I am fairly certain those dreaded BPAs are in the lining of the bladders, so when money
and time permit
we will upgrade to HDPE or stainless tanks
I take it you are referring to a chemical type taste, because if it's not a chemical taste perhaps a critter got into your tank somehow? Dead frogs are well known for making water taste disgusting, though rats and possums are worse! Just added that to help you smile: fresh water is one of the MAGNIFICENT joys of cruising so do whatever you can to remedy the problem!