It's a fact small pools can often be much tougher than large lakes. Take twenty carp and put them in a large lake. How long do you think it would take for them to know every single area of that lake intimately? If they could ever achieve it. Now take those same twenty carp and put them into a secluded little pool of two or three acres and ask the same question. Having fished a variety of small to medium sized lakes and pools over the decades the one thing i have noticed is 'Switching off'. You get to the lake and you see the carp everywhere. You catch one and then they simply vanish for days. This wonderful old character @17.8lb was stocked back in the early 80's and knows every inch of Valley pool. I caught it within half an hour of moving, then it went totally dead. I think short sessions are the order of the day:-)