The size of the ingredients that go into the gritty mix is intentionally just slightly larger than the particulate size at which the perched water table disappears. Larger particles increase aeration but decrease water retention. Smaller particles decrease aeration, increase water retention, and support perched water. That doesn't mean you can't still have plants that respond much better than if they were in heavier peat-based soils that support lots of perched water, but you need to be aware that it's (PWT) there & work around it.

I would use a wick through the drain hole to help drain the PWT - at least until the roots have colonized the entire soil mass & the extra water retention might be viewed as a +. Grower size grit is the size you want - or #2 cherrystone. Not the end of the world, but you do need to be a little more careful with the watering can. ;o)

Al