Measure 2 1/2" off of the concrete wall that you wish to attach to and mark for your first hole of your Pool Fence DIY and resume laying out as normal.
Once you have drilled and put your fence up you will need to attach your fence, you will need to drill a hole and use a concrete anchor. Put your latch that comes with your Pool Fence DIY onto the pole and use it to place a mark where you need to drill a hole. Then insert a concrete anchor that your eyelet will screw into. Last simply attach your fence to the concrete wall.