Since it is a potting mix, I would use powdered rather than pelleted lime. You want the neutralizing effect to be rapid. I think pelleting of lime is only done so it will spread more easily and uniformly with a mechanical spreader.
And be less dusty.
Maybe pelleted lime falls apart so easily that it might not matter a lot. I never bought pelleted lime: too cheap.
May I add a question? When you-all add lime to a potting mix, do you insist on dolomite lime? Back when I used it on lawns in New England, the "conventional wisdom" was to always use dolomite lime because the Mg it adds was needed, and all-Ca would be undesirable.
But now I've learned that what is "always true" in one region may be "usually false" in some other region.
And pots are not lawns.
