I've always had the most success when my Alk is around 7-8. I shoot for 7.5ish. However the most important thing is for the alk to be stable!
At one point I was testing daily but then moved to twice a week. As soon as GHL releases their KH Monitor I will be sold. KH, is imho, the most important parameter to check on a regular basis. Too many things can go wrong if alk swings up or down... And the crazy thing is all it takes is hours/days for things to go bad.