I got an Orca 64 ounce water jug for the boat, dogs, etc. I filled it up about 3/4 with ice and topped it off with water on Sunday morning at 10am. I added water twice more on Sunday. This morning, 1/3 of the ice was STILL in there. I haven’t had the lid on since 4pm Sunday and have just been watching to see how long it takes.
If you like ice cold water all day like I do, these things work great.