How long does your co2 last?

[sphelps]

I use to get about a year out of my 10lb when I had it, then I switched to 5lb to save space which for some reason would only last about 2 months. No leaks, same tank, same reactor.

So I would definitely you're going through it too quickly and something isn't working properly but I assumed the same when I switched but couldn't find a problem. So.....