http://www.wasserstrom.com/restauran...Product_385655
http://www.amazon.com/Clear-Deli-Con.../dp/B00115MUVU
http://www.webstaurantstore.com/choi...7RD16BULK.html
Just buy the 4" coupling. You don't need to attach it to the tub, just set it in the tub, then fill the deli cup with water and drop it in the coupling. They will not turn them over. They are cheap, easy and convenient.