If you plan on having them turn of and on a lot I would get something else. People claim they sometimes start in reverse. One day I found my puffer half in the powerhead. It looked like it backed in tail first. I assume that it started backwords from feed mode and sucked the puffer in. That is only my assumption on what happened. With that being said I still use them, I just took it off the feed mode feature.
If you are going to constantly run it or use it for water mixing they are fine.