One of the benefits of a grow wall is not having to clean the aquarium or do water changes to keep the fish healthy. A grow wall is an awesome biofilter. Just keep the water topped up and feed the fish.
I do have one caveat. Don’t purchase fish that require a brackish environment, like mollies. They don’t do well in salt free water. Salt in the water will do ugly things to the plant wall so stick to fish that don’t require salt.
Here’s a link to a site that offers insight on which fish to start with.