Not entirely true. It is true that slime grows at dead spots more but that is because your nutrient level is high. If you know, red slime is a kind of aerobic bacteria. i think its duty is related to nitrogen fixation which basically is your ANN cycle. so you have more nutrients, naturally mother cyano produces more of the baby cyano. So to combat red slime, control your nutrient level first.
You might want to get a bigger skimmer or do more water changes.