It will still be effective as long as you properly follow the directions.
Going cloudy can be a sign that it's lost effectiveness, but when it does it pretty much immediately, it only means two things. One, that you have hard water, and two, that you can't use clarity/cloudiness to gauge effectiveness with that water. It'll still be good to use though, end of story.
If you're still concerned, then test it with a pH meter. If you're an all-grain brewer, it's really something you should have anyways.