Found out that even though decaf coffee has no caffeine it still is a diuretic. I thought we could count decaf towards our fluids. I'm confused.

yeah, I drink decaf on occasion and I can attest that it still has a small amount of caffeine, is still a bit diuretic, and still causes acid in the stomach. Not a great choice for sleevers, especially early on. I have it once a week or so. When I do have it, I count it towards my fluids. However, on those days, I almost always have to drink extra water because I'll get thirsty.