Vinegar babe x
White vinegar also good for the sterilisers
Yes vinegar
Once you have de scaled a little tip, stop using tap water and start using water from a water filter jug to fill the kettle I find this stops the kettle from scaling up so bad x
Citric acid works wonders. It will lift up even the toughest limescale
Not formula feeding but I always use food grade citric acid and I feel it works better that Oust and other stuff