I learned my lesson the hard way on a Rio pump....
Its a long story, but basically we had a power outage that flickered on and off once or twice, then came back on. Everything in my tank looked perfectly normal...The next morning when I got up, I could smell that something was up in the tank...It was really early and I didn't investigate it thoroughly enough (hugest mistake ever)...I got a phone call from my dad about 10 am saying that my tank was all clowdy and all my corals looked shriveled. I immediately started to rush home. By the time I got there 45 minutes later, everything was dead except my male clownfish... It was one of the most traumatic experiences of my life. I had to set up a QT tank for him with some non-toxic water in like 5 minutes and risk putting him in there unacclimated to it. As we tore down the tank, we searched for what could have caused this....It was a rio pump that (I believe) had gotten "stuck" via the power outage. IT was trying to pump water, but it wasnt and it ended up leaching toxic fumes into my tank.
Moral of the story: Don't skimp on your equipment....always do your research and make sure you purchase the nicest equipment you can afford for your tank....Oh, and ALWAYS check and make sure all your equipment is still working after a power outage...