How to switch to a refill routine without wasting money
The maths only works if you finish what you already have first.
1 min read
Start with the bottle you own
A concentrate is only cheaper if it replaces a bottle you would otherwise buy. Buy one refill, use it in the bottle on your counter, and only then decide whether to keep going.
Check the dilution ratio before you buy two
Two concentrates with the same price can differ by a factor of two in finished litres. The ratio is on the pouch; the finished volume is in the product title.
Do not stockpile
Concentrates keep, but not forever, and a shelf full of pouches is the same money spent earlier.