This is actually a commom problem with strip readers and strips...this is why pool stores that use strip readers have such bad testing results! LaMotte has just come out with a portable colorimeter called the ColorQ.
http://www.lamotte.com/pages/pool/newprod.html
http://www.lamotte.com/pages/common/...truct/2056.pdf
It uses liquid reagents except for the CYA test which uses a tablet reagent. LaMotte has a lot of experiences with colorimters so I would be interested in how well this inexpensive one works!