Your circuit is good for an indicator. But with it, the pump will switch off as soon as the probe touches the water. This may cause sloshing. The probe is then briefly out of contact with the water and the pump will restart. This can also cause sloshing and repeats the cycle over and over very rapidly. A second, lower probe with a flip-flop will prevent this, with only a few more components. This is how I remember it: attached.
I actually use a version of this, except with a micro-controller instead of a flip-flop, to automatically maintain water in a Christmas tree stand.
Ken