There is a "water bag" thingy sold for pickup beds up north that is filled with water in the winter to add weight. I can't remember where I saw it advertised. Maybe do a google search. Sounds reasonable and would be easy to drain and remove.
JPudenz said:I appreciate everyones help... I have decided to go with the concrete idea, seems like it would make a great bedliner...
Seriously I will probably just try the sand bags.
Thanks,JJ