well the exact ratio is 3.5% of tye water volume

however you should not  spray on and let dry! it should be rinsed offno lonfer then 2 hours aftrer spraying on!

really it does all it needs to do in 10 minutes

leaving it on can fry the hair

exception to the rule however is the pink sea salt from dreadlockshampoo.com wich has vitamins and proteins and herbs good for the hair so its somewhat safer to leave in (atleast from my testing it seems to be)

but sea salt should always be rinsed out otherwise, or used before, or during your wash

You can use 1tbspn + 16oz hot water. Dissolve salt in water and spray on hair. Let it air dry. It helps to tighten.