I agree with everyone and would drain that ASAP like lol today ASAP after you get some tubs set up. The longer you wait the more risk you take and less chance the place will swap it out. I hope it works well for you and is only silicon, but keep us updated. These issues definitely need to be done quickly.
Hard call ! Before we all say replace, consider
Only 16 gallons & the crack is at the very top so very little pressure . . Maybe a big glass patch on the inside with a lot of silicone would do the trick. It's on the side so might not look too bad. It's a hair line crack doesn't pass thru the glass,so still has some strength.
If Mordie is tight on the bucks, I'd say go for it. I have done this in the past & worked just fine . If He has the bucks replace it by all means !