How accurate are Walmart pH test strips??

because APPARENTLY my pH of the water ive been using is like 8.4?!? It has actually worked fine is why im surprised that the pH would be so high?! How accurate are these strips supposed to be? Has anyone ever experience anything similar?

they are ok, but their range is relatively low. the droplet type for aquariums are better (slightly larger range), and the droplet kind from a garden store are even better than that (even slightly more larger of a range). but, if money isnt an issue, skip these trashy and 'not-quite-as-accurate' tests, and just get a pH Pen. full range, very accurate (so long as its calibrated properly).

does your soil contain dolomite lime or something to control ph? that would be my guess. They are fairly accurate. I used em but i got mine from work since we are supposed to test it 2 times a day. do you mean these things?
http://www.htgsupply.com/viewproduct.asp?productID=49723 A pen is a good investment but those will work in a pinch.

ph the runoff and see if it is lower than the water you've been using. a lot of nutes and stuff in the soil will lower the ph. your nutes or medium may be adjusting down the ph for you. i've never used strips, just the drops. the drops from the hydro store are very accurate, just hard to use with a cloudy or tinted solution. don't bother with the cheap probe ph meters. i have used 3 different brands and they are all equally useless.