Waterbed Cylinder Tube Complete Mattress Set. Available in FreeFlow Tube. Buy your softside waterbed tubes as a complete mattress set and save Softside waterbed tubes allow you to fine tune the feel of your softside waterbed. With a tube system you can easily fill or drain the tubes at your faucet without the need for complicated (and additional cost) fill and drain kit systems. Each tube is a manageable weight and closes securely to transport to your softside waterbed. With a tube system you can easily attain a different feel on each side of the bed. By underfilling one side you can achieve a softer feel with more wave action. While your partner may prefer a firmer bed feel, you can have the full-motion waterbed that you prefer. Many couples have found new nighttime peace with a tube-style softside waterbed. You can even mix-and-match free-flow tubes with waveless tubes to really customize your bed and find the perfect sleep. Available in Free-Flow or Waveless Tube Cylinder. We recommend you purchase Tube conditioner tablets with the purchase of any new tube(s). Most Common Tube Sets/Sizes: Twin Mattress: 5 Tubes Double Mattress: 6 Tubes Full Mattress: 7 Tubes Queen Mattress: 8 Tubes California King: 10 Tubes King: 11 Tubes. Twin, Double, Full take 66in tubes; Queen, King use 71in tubes; Cal King uses 74in tubes.