Thanks to an astonishingly generous $100 donation I was able to purchase three black Otterbox 3500s needed to hold the lead block weights, which will weigh down the new habitat. The leftover amount will be used to buy the water bottle and running saucer. I still need money for the weights, but I'm sure that'll happen at some point.
Anyway, thanks for enabling my flagrant mental illness which for whatever reason manifests as the urge to build functioning scale model underwater cities for rodents! You know who you are. I really appreciate every donation, big or small. This is a weird hobby but very fun to do and evidently fun to spectate. I'll keep doing it as long as I am able to.