AS will also "trick" a non-feeding plant into thinking it's time to feed, again. I mix it in all my gly. apps., this time of year (for that reason, alone). Yes, it is a hard-water ad-mixture. But, it has the residual efficacy I mention above, as a bonus. I've done tests with and without......using several different water sources.
If you haven't tried it, I'm just making a suggestion.