Share 'Solution for the sticky wax?'

I have refilled my lava lamp with my solution,using epsom salt,with -1/2 litre purified water -around 2 spoon of salts --1 drop of soap I've fiddled with the exact solution,by adding or removing the water until level,but after a few months the wax tends to have some little nodules stick to the bottle insides.the wax will usually welts off,but leaving two or more bits of wax.The solution is clear…