Buyer beware - under-filled propane tanks!
 

It's no secret both Lowes and Home Depot get their propane tanks supplied by Blue Rhino and Amerigas. Well, these two companies only fill their tanks to 15.0 lbs., or about 3/4 only! Not only is that a rip-off, it is forcing people to change-out their tanks more frequently causing more gas driving to and from the store. I recommend getting a Grill Gauge (grillgauge.com) and use it to verify your tanks are correctly filled to the maximum DOT allowable levels!!!

Chris S.

It's my understanding that they only fill them so far to account for pressure expansion.
Have your tank purged upon refill to get the maximum. Go with refilling versus swaping to avoid any issues.

What pressure are they supposed to filled to? It seems like leaving room for expansion of gasses might be a good idea.

Propane tank weight
 

It's not about pressure, it's about 'weight'. A legally-filled tank should weigh out between 38 and 40 total pounds which includes the tare weight of the tank. I found out the Grill Gauge is calibrated for this as well and therefore is the most reliable way to measure propane in a tank...

The tare weight is stamped on the tank (TW xx), just weigh the tank and subtract the tare weight and you have the amount that is in the tank

Texaschamp:
You make a good point, but for the accuracy needed, why would you want to spend money on one of these:

http://www.grillgauge.com/images/gg.jpg

if you could use one of these:

http://www.justgobow.com/wp-content/...le-300x300.jpg

This under-filling is not an error on the part of Blue Rhino or other suppliers. It is a deliberate under-fill while charging you the same price they did when they supplied a full tank. Use these from the grocery store, Lowes, HD etc only on Sunday afternoon when you run out and no filling station is open. Otherwise, use a propane filling station and you get a full tank for less than the cost of Blue Rhino or others. You can take the labeled tank in to a filling station and get it filled. The tank belongs to you once you take it out of the cage at the store.

gator