Just a personal opinion because I really do not know for sure concerning GSE...

But usually an anti-bacterial, things of that nature, are good off and on, a few days here a couple there. Reason being, they can also adversely affect good bacteria in your system so just use it to keep things under control now and then.

The GSE is very effective within just a coupe days, I like it a lot. Mine was expensive though, but it's a good size bottle I will probably have it for another 18 months. I should put it in the fridge.