The great thing about a scrubber is that it grows exactly what many fish eat naturally. Even fish that you think would not eat algae, such as some cichlids, will do so if the growth is living. But many freshwater and saltwater fish and other animals love it. Green hair algae especially, but also...
Here are my Blue Ribbon eel vids from 2007 to 2011, showing the progression of the eel and the feeding:
https://youtu.be/Z-czlAYmvzM
https://youtu.be/HLi5-GBRMNk
https://youtu.be/E1s9DagZzW8
https://youtu.be/f7aWtixmND8
https://youtu.be/ynxAlnvgy5w
https://youtu.be/9Kk3vAN1Y3g...
The new DROP-10 has water circulation holes small enough to keep almost all livestock out; this way you can keep livestock in your sump without them eating your filter.