Your search for "potassium citrate effervescent tablets" revealed the following:

Sale price £29.99 Regular price £40.00 Sale
Sale price £164.60 Regular price £200.00 Sale
On Sale from £99.79 Regular price £130.00 Sale
Sale price £89.53 Regular price £130.00 Sale
On Sale from £96.10 Regular price £110.00 Sale
On Sale from £79.70 Regular price £90.00 Sale
Sale price £26.28 Regular price £30.00 Sale
Sale price £87.64 Regular price £114.81 Sale
Sale price £83.04 Regular price £90.00 Sale
On Sale from £81.47 Regular price £90.00 Sale