I live in Wisconsin and my man made watering hole is dried up. I was going to buy a 15 gallon rubber tub from Fleet Farm and put out for the deer. Is that big enough and should I go with plastic or a rubber tub. I own 40 acres and have some nice bucks on my property, also can I just set tub out or do I have to bury it in ground. I will keep water filled as I check my cams. Thanks Scoot