Ya I never build farms past the first or second tier the population simply grows to fast.
Another tip is when your conquering towns if you havent already dont enslave them, its good early in the game for cash and growth but when your towns are burgeoning later dont do it simply exterminate for cash and quiet.
Another tip when you conquer an enemy town is to destroy their temples and replace them with your own that will eliminate some culture difference and make them more quiet as well.