But if you're generally light with the product application, Dr. Fusco points to the water in your shower, instead. "'Hard' water can have an affect on hair and scalp, leaving it sticky and with residue," she explains. Hard water is defined as water with high levels of calcium and magnesium deposits. These can wreak havoc on your hair. To fix this problem, Dr. Fusco suggests swapping in a water filter, like this one from Raindrops. [Ed. note: Aquasana makes a great filter for half the price, too!]For everything else? You're in luck. "Scalp skin changes [regularly], in that every 25 days, there are new cells that have replaced old cells," she explains. "So the good news is that you can effectively treat your sticky scalp quickly with the right products."Her first suggestion? "Shampoo reguarly!" she says. "Pay careful attention to rinsing thoroughly." She also says that if you use a lot of leave-in products, double-shampooing may be helpful.Dr. Fusco reminds us to think of our scalp like our faces — if it's sticky, you'd cleanse it, right? You wouldn't just layer more product (ahem, dry shampoo) on top of it to fix it. "The same holds true for [your] scalp, which is an extension of your face skin," she explains. So don't be afraid to lather up! We'd prefer shampooing daily to a sticky scalp, wouldn't you?