I posted that rather hastily. Hadn't considered that the tank would be outside the water bath. Still, I might just manually roll it on top of the tempered water and see what happens. And cutting thirty seconds sounds like a good idea.
And, as a matter of fact, they are Holga images. But I do have one of a semi-famous, fully pompous, operatic baritone in costume, that I'd like to see come out.