Great water but slow fishing

Headed down to a small creek for the day with Mark.  The weather was perfect, the water was low and clear and we had the water to ourselves.  I tied on a pmx while Mark used a Chubby Chernobyl.  We walk down about a mile from the car and start fishing our way back up over the next four hours.  We can't figure out why the fishing is so slow with all the good pools but the action never picks up and we finish the day with 5 for me and 3 for Mark.  That being said it was a beautiful day and we were fishing!