One minute in every ten sounds like a lot to me. I have a commercial timer that comes on for 6 seconds every 6 minutes, but it is expensive. I then tried to duplicate it and build one myself. I built one that comes on for 10 seconds, every 10 minutes (close enough) for just a few dollars. If anyone wants directions, and diagrams, post here.

Here's a link to the directions. Keep in mind two things.
1. Since these directions were written several years ago, prices for some components may have gone up somewhat.
2. You need an old fashioned clock; the kind with the hands that go around, not one with a digital read-out.

Here is a link that might be useful: Mist timer