How do you know when the Automatic Paste Pump is empty?

When you arrive at the Automatic Paste Pump after 5 or 6 months, the foil case will feel firm like a blown-up balloon. This shows us that all of the gas within the pump has been released, and all of the paste has been pushed out. 

If it’s been longer than this, the Automatic Paste Pump might have deflated and have a bit of a saggy feeling. This doesn’t mean it didn’t work, it just means that the gas has permeated the foil. The gas that's in the bag will eventually sneak out making it feel soft. This happens over a very long period of time, and will not be an issue if you’re replenishing your trap every six months.