OFFER: 10kg of oxalic acid dihydrate (half of a 25Kg bag) (Caversham Heights RG4)

10kg of oxalic acid dihydrate (half of a 25Kg bag)
OFFER
10kg of oxalic acid dihydrate (half of a 25Kg bag)
Caversham Heights RG4
DESCRIPTION
It was used to clean oak tannin stains off my patio.