testing for hard water?

i was wondering if there is a cheap way to test for hard water? i was using BS wash but it was making my hair and scalp gross, but there are no other signs like buildup on the shower head or anything....

updated by @andrea-schneider: 01/13/15 09:06:37PM

• "Take a clean empty plastic bottle having a cap (such as a clean, clear pop bottle);
• Remove the cap;
• Open your tap water faucet and fill the bottle with about a half-cup of water (8 to 10 ounces);
• Add 10 drops of dish washing liquid;
• Shake well;
• If the soapy solution foams up quickly you are good and the water is not hard;
• If it does not foam up but instead creates a milk-curd-like or soapy film on the water surface then the water is likely hard."

I believe this works if your water is really hard. Our water is somewhere in the middle between extremely hard and soft, and as i tried that experiment, the dish washing soap foamed, but not as much as one would expect it to foam.

I hope this was helpful!