slightly stained and warmer is good, seeing cavitation plate is good seeing prop is better. Temps can be deceiving as you are reading the surface temp. Can be very different down a bit. If you have what you think is good water and marks but no bite, move, It is probably too muddy down at the fish. The water clarity can be different below what we see. It could be more clear or more muddy, one only knows? I wont fish good marks with no bites for too long and waste the day. There is usually a water clarity issue preventing the bite, especially if the fish are suspended and not catching.