Finding 6" diameter PVC is near impossible at Lowes and Home Depot since the largest diameter they carry is 4". Once you add the cost of end caps, etc. it's fairly expensive too, but that's not my problem, I can't even find the pvc I'm looking for. As such I am turning to the monovault, however, I've had bad luck with the gamma seal lids on my food storage buckets. I've had 2 gama seal lids crack completely. They were never stacked on top of each other or anything, they just cracked around the ring over time. Very lame. The only thing that makes me wonder if the monovaults will be any better is the protective cover lid that screws on over the gamma seal. Anyone have any feedback on these? Are they worth the price? They are rather expensive too, but at least it is easier to get.