*Hypothetically speaking* A Simple rule - No more than 50ml of water for every 20 tablets used Adding ice cubes can help speed up the process but not too many or it will increase the volume of water way too much. Cold water extractions work best if no hot water is used only cold water, just crush the tablets into fine powder, a big plastic bowl and a smaller glass bowl will work best "although it takes some doing" before you put the tablets into into ice cold water. Tried many times before *Hypothetically speaking* with a better result all round. Put the solution into a container "A glass Jug works best" then place the jug in a big bowl full of cold water and ice "if you have any ice too hand". Let the solution cool in the fridge for as long as you can wait ideally 8hours. You will know it is ready when you can almost see through the liquid and all the asprin has settled to the bottom of the jug. Filter out solution using what ever you have too hand, a dish cloth works well. Store in the fridge if possible. Drink and enjoy