What are you trying to grow? The key is to keep ca and alk in balance. Elevated ca/alk has been known to slightly increase growth, but has more to do with the elevated alkalinity. As you near the upper end of alkalinity you lessen the "wiggle room" of keeping it within the recommended range. I prefer to keep the calcium around 425 and the alkalinity around 9dkh because it is right in the middle of the range. If it creeps up or down you have room either way.
To answer your question directly, increasing calcium alone will not show increased growth. However if you also raise the alkalinity in balance to the calcium at 450 you will see an increase. Also keep in mind that magnesium will need to be 3x the targeted calcium so that the water will hold it. Here's a chart for ca/alk balance.
