Quote Originally Posted by alisonquilts View Post
The only reason I am so curious is that I am sure I read a thread which mentioned a couple of chemicals that would precipitate if you added them too close together
That's when you add calcium PLUS either sodium bicarbonate (Alk Increaser) or sodium carbonate (pH Increaser) at the same time. You have a vinyl pool, so you NEVER need to add calcium. (Problem solved!)