I bought another 5 lbs at my last trip to the store, just to save a trip. Should I put some of this in (dissolved in a sock) to bump it up a bit, or should I save it for the inevitable rain storms that have been hitting the midwest? I was told that stabilizer should last a whole season, but with all the draining and backwashing I've had to do after storms, I'm sure I've lost a lot of it.