We just bought a new spa less than a month ago. Everything was working fine until today. Now when the pump is shut off it makes a whining sound for a few seconds. It makes no odd noises when running in either speed and seems to work fine except when you turn it off. Like I said, this is a brand new spa, but we got it cheep from a local business going out of business and there is no warranty. The only thing I did differently just before the spa started doing this was add a bottle of PH locker. We were going through a lot of PH - and thought this might help. I'm currently draining the spa, as I have found a very small leak near the heater unit too that I'm going to fix. What's your thoughts on this pump? Is it safe to use?