Do i repot if i overpot?
 

I accidently overpotted one of my phals a week ago, should i repot it or just water it less based on drying time?

I think the answer to your question depends on how badly overpotted it is, how fine the substrate is, and how quickly pots dry out in your climate. The problem with watering less is that it doesn't do anything to speed up how quickly the center of the pot dries out, which is what leads to problems.

It's only been a week which is nothing in Phal timespans, and if it were my plant and was indeed massively overpotted, I'd probably repot since Phals really do prefer a snug fit.

I agree with Camille. Also, take the plant's health into consideration. If the plant was struggling or sitting idle/dormant, or if the roots aren't in the best shape, that would lead me to repot into a more suitable-sized pot asap. A healthy, vigorously growing phal is likely able to do just fine slightly overpotted if all other aspects of care and growing condition are suitable.

If all you have is an oversized pot you can invert a smaller pot on the bottom before potting the plant so there will be less distance from air to the innermost medium.