If your dosing via ATO, results should be instantaneous. You will either see a decreased daily consumption of Ca
or, ideally, a constant value. Tweak as necessary. Keep in mind, lime is a better maintenance dose than a raising dose.
One of the benefits of lime is that it purifies itself after mixing. That layer on the bottom is trace impurities that have precipitated and settled. I clean it out every few batches; it won't dissolve back into the water, do its safe in your container as long as you don't pump it into your tank.
Another side note: if you mix lime into salt water directly, instead of RO
water first, it will cause a precipitation snowstorm of Ca
& other beneficial elements.
Good luck & keep posting.