I am not really a grinder I play to have fun. But I earn about 300k ec/day and spend half of it on reputation.
I earn about 6,000 dil/day give 500 to my fleet, convert 2-3k to zen (20-30zen) and stockpile the remainder.
I also do one to four email spam free zen specials per week. Not the surveys, go further down the page and there are offers to sign up for email. They give between 35 and 68 zen. The occasional 3 zen to watch a video too.
So it works out to about 65 zen/day if I average my monthly total and divide by 30.