Spent today learning more about the water mechanics. Built an above ground aquarium style crocodile habitat, a below ground croc habitat with a cave-style underground viewing spot next to it, and finally a seal habitat with a fully underground tunnel they can swim under. All three will need some decoration (the underground tunnel doesn't even have a glass ceiling!), but I was mostly practicing the game mechanics for the future. Thinking I may try hippos or pygmy hippos next, to continue to work on my water skills.
A few of my previous habitats started saying they didn't have enough deep water, despite having checked them so carefully when first created. Discovered that it appears to be a calculation bug, and that I could fix them similar to what I do with the climbing bug that I get often -- just move any item that will allow it to recalculate again, and voila!
Still uncertain how much I'll do in this week's Community Challenge. I'm thinking I'll probably need to save most of my silver-plus aquatic animals to populate other zoos, since most of them are still new for me (including crocodiles, which I'm not sure why I never got before), and I definitely want them to be in a lot of future zoos. But I do have some baby gharials in one of my other zoos that I may try to age up before the challenge ends, and of course, might get lucky with the breeding and have a surplus to release too.