I have plastered a few walls in the past, with great results however today i was plastering a large wall

Comment posted to Learning to Plaster by Plastering and Struggling with Drywall by ted.

i have plastered a few walls in the past, with great results however today i was plastering a large wall and when i was smoothing the second coat out ,wet trowel, i noticed a load of cracks appearing in one part of the wall only , am i right in thinking my water was to dirty and setting to quick or had i missed that area with pva and it was sucking the moisture out off the plaster faster than the surrounding areas