Undervolting DC pump

I am running a jebao dc-8000 (it is a DC pump) return pump on my 75 and I am running the risk of overflowing the tank if power goes off and it goes to highest setting after it resets. Was thinking of undervolting the pump like running it at 18v instead of 24v (using variable volt adapter) to lower the output a bit. Any thoughts? Will this burn the pump long term?


thanks for looking