Swamp cooler cold enough?

To cold crash with Knox gelatin? I really want to clear my beer before bottling and I've read that the colder it is the better the gelatin works. I have room for frozen water bottles in my tub.

If you have a lot of ice to keep it cold it's possible, but you'll probably have to change out the bottles frequently (especially at first) since the relatively warm beer will warm up the water bath somewhat quickly. But once the beer temp gets down to around 40 or whatever the water bath is, it will hold the temp better.

So, you can give it a try, just be prepared to do a lot of fussing with ice and/or ice bottles for the first few hours while you fight to bring the temp of the beer down, and then maintain it for at least a couple days. I'm a lazy brewer so that's far too much work for something that will happen on its own with time anyway, at least for me.

You don't need to get the beer cold when using gelatin, but typically if you use it while the beer is in the 40s it will clear in a matter of days as opposed to a couple weeks at room temp.