I think if anything, with the use of diatomite you need to watch and measure how much water a pot might need, and this will of course vary as the plant growing in the pot gets larger and requires more resource.
The reason I say this is that when making mixes with a major diatomite component I will wet the diatomite to suppress dust. It is surprising just how little penetration is achieved with 9ltrs over a 35ltr amount of diatomite, the water barely reaches the bottom. Also the amount of dust and muck that comes off Mount Sylvia Diatomite is not that great.
If you are using diatomite at 40%+ in your mix its probably a good idea, (just like with any mix) to use the 3 W's.
Water

, wait

and watch
Observe how the water is moving through the mix in the pot.
(if there is another W word that you can tack on there feel free (maybe wonder

)).