I wouldn't rely on the strip test for anything at all, honestly. A basic liquid pH test kit isn't expensive and it's much more accurate.
When it comes to breeding in general, don't start making changes until you start having issues. Now if you have a mature healthy pair, fed well, frequent water changes, etc, and they aren't spawning, that's the time to start adjusting things. But generally speaking, the less things you change, the better, at least if you want to keep things simple.