you can have too much SCA in your coolant. iirc, the SCA will precipitate back out (ie: undilute, like too much sugar in your coffee) and can clog cooling passages and lead to premature water pump seal failures.
its better to be slightly low on the the SCA range of the test strip than to be too high.
drive it around a little bit and make sure its WARM when you check it. if its still too high, drain some coolant out and save it. replace with fresh 50/50 mix.
if you have a coolant filter setup, you can get filters with SCA tablets that release over time to maintain proper SCA levels.
dennis
how many miles on this coolant? is it bright green or dull green? when was it last changed?