you shouldn't ever do 50% water changes, this removes too much of the beneficial bacteria that keeps water healthy, i would recommend 1 25% water change per week, also, if the ammonia is not the problem with the ram, it's gill flukes, i treat it with pimafix, it is mild enough that it nevers bothers my rams but almost always cures them, in your case however, when they're on their side on the bottom, it's almost always too late
P.S. if you don't have any salt in your aquarium, you NEED it, especially if you want to continue keeping rams, it is ESSENTIAL to soft water and keeping infestations at bay, i use close to 1 teaspoon per gallon
good luck!!!