We did feed Wellness, which sound so good, but they pooped more on it and we thought maybe their bodies weren't using enough of it Not sure on that though. What do you think?
This is a common problem that people are having switching to Wellness. Not sure why, it's a great food. I've seen tremendous health improvements from dogs who were doing grocery store foods switching to Wellness.

Something that I tend to tell my customers when they ask which is the BEST dog food available, it's not about which is best, it's about what's best for your dog. You look through the ingredients, take out all the crap filers and you're still left with tons of foods to choose from... Find something in your price range (1), find something your dog likes (2)
Keep trying something until you find something you like, but, to see the benefits of any new diet change, I always encourage my customers to give it one month to start noticing any change in stool, coat, breath, energy, etc... (of course, if the dog just refuses to eat it, try something else)
I rotate my foods every three or four months, and my first step in elimating foods: if it has lamb in it I won't feed it. It makes my dogs gas far worse than it normally is. But, lamb, maybe just the thing your dogs need...

This leads into my other thought about why (possibly) Wellness wasn't you best option... Since you were feeding a lamb formula (most Nutros are) before and switched to Wellness chicken, the dogs digestive track could just be very not liking the protein source switch. Dunno. But, If you switched them to Wellness chicken before, I'd say try switching to Wellness lamb (if you're up for a couple week experiement) Or even try another food that's lamb based, like Natural Balance or Sensible Choice Lamb and Rice (<--this might be a good start for you, it's a step up from Nutro because it's eliminates corn from the food.)

Just some thoughts.