I have this dilemma every year in August. I can't seem to find many big carp that are willing to hit in the daylight hours, but I know where there are good numbers of fish in the 5-10 lb. range (see pic of recent catch) that are more than willing to do battle. These are small fish in the carp world, but fish in this size range can be terrific fighters. So, rather than blanking while trying for the big ones, I usually opt for the action of smaller fish.
I was out trying the last two evenings. These were short sessions of a couple of hours an outing. Last night I landed 6 carp and the night before I landed 4. That's 10 carp in the last two outings, a total of 4 hours of fishing. Not bad for August. The hot bait has been sweet corn, although it keeps getting picked off by turtles and horned pout. If I could keep bait on the bottom, I had a good shot at catching a carp. So, I've learned to pull in my lines and check the bait every 20 minutes. All the fish in the last two outings were mirrors in the 5-8 lb. range.