My problem is I only have two plants, and one tiny offset on one of them. The two mature rosettes are the same size.
I had already thought about building a cardboard spray booth around the test subject, so I would have any drift to anything else in the neighborhood of the test plant.
Tomorrow begins the experiment.
I will mark my calendar and note any changes to both plants. Hmmmm, maybe I should detach the one year old offset and make it a test subject also?