How to remove tannin stains on the newly installed Merbau decking?

[BB_Hawk]

Hi

I just installed a Merbau decking but used the tarpaulin to cover it for a couple of weeks. There was rain during this period. When I remove the tarpaulin, there are noticeable stains on the surface of the decking, I know these are bleeding tannins mixed with water, but please advise whether I can still follow the weathering process to let it go, or I have to use the chemical product to wash them out?

The wet deckingThe wet deckingThe dry deckingThe dry deckingl 

Thanks

Hawk