I highly recommend reading "Not the end of the world" by Hannah Ritchie, particularly if you picked D or E. It is written by an environmental data scientist who is also a climate activist. She examines the actual data for climate change and other environmental problem as opposed to extreme...
I have a 2200 gallon koi pond running an Oase proficlear L compact and 110w EV aqua UV with skimmer and bottom drain. The pond is massively over filtered (a good thing) to be honest but I ordered the drum before the pond was built and it ended up a lot smaller than I anticipated. I would have...