MOVING ACROSS TANKS OF DIFFERENT PARAMETERS
The main issue for both plant/livestock is that while many can survive in a large range of GH/KH values, the transitioning process from water with different GH/KH can be stressful.
For example, Red Cherry Shrimp can be found thriving/reproducing in tanks with as low as 1-2 dKH as well as tanks that have much more alkaline water, at 12+ dKH.
However, if we transfer shrimp directly between these 2 tanks, we will lose a good number of them due to osmotic shock as the KH value difference between the two tanks is very large. In both tanks, the shrimps have adapted to their water parameters.
when drip acclimatisation works...
I find that for sensitive species such as dwarf shrimp, transferring them between tanks with KH difference of 3dKH or more is stressful & potentially deadly. The symptoms of osmotic shock are often not immediate - it takes many hours/couple of days for things to play out, so seeing livestock moving around the tank environment in the couple of hours after adding them to the tank is not the correct way verify whether livestock is suffering from osmotic shock or not.
One way to get around this problem is to buy livestock from dealers that have similar water parameters to your own tank - this is especially so for sensitive species. If the difference between tank water is small <3dKH, drip acclimatization across many hours will work to minimize stress.
and when it may not
Drip acclimatization does not work for large parameter differences
If the difference is large, for example, 10dKH, drip acclimatization will not be enough. The impact of water parameter shock is often not immediate; the livestock weakens and expires over the next few days.
In such cases, you can place the livestock in a holding tank, and raise the parameters in a holding tank slowly, 2-3 dKH a week, until it reaches the target required parameters of the main tank. The much easier option is to buy from dealers that hold livestock breed in water similar to your tank parameters.