Well spotted 😁, it doesn't help when there's Imperial Gallons and US Gallons as well, at least litres are the same volume throughout the world.@Zeus. and @Happi. You are both correct. The problem is the unit and the fact that Red Sea did a rough approximation of what Liters are in Gallons or vice versa. Technically 100 L = 26.4172 Gal (or inversely 25 Gal = 94.6353 L) but I assume, for the sake of simplicity, that Red Sea simplified that to 100 L = 25 Gal. See below.
That will be the French man coming out in you 🤣 But metric all the way in my book - well except for 'miles per gallon' never got on with 'km/litre'. We are just as bad in the UK as we drive in miles and buy fuel in litres, although I think they only changed to selling fuel in litres as it sounds less putting tax on fuel up 5 pence per litre than say 20 pence per gallon - which the later is less.
So if we are using MgCl2.6H2O and MgSO4.7H2O as our salts (the little yellow box is the sulphate/chlorinity ratio of the dose)sulphate/chlorinity ratio of 0·14000 ± 0·00023” which is the ratio of Sulphate to Chloride in Seawater.