Because of the previous data comparing the open box vs the closed box was varying unexpectedly, I re-ran the experiment with both sets of data taken on the same day. 

• The closed box data was taken from 8 am to 1 pm on 8/9/2019
• The open box data was taken from 1:45 pm to  6:40 pm

Now both sets of data show very similar curves, with the box open data slightly above the closed data in most areas. Maybe the last data was different due to other systematic conditions on that day, but it does seem like now the difference is gone. Both sets follow the original closed box data measurement from before.