Adding carapils? How much rice is to much?

[lalnx]

My next 5 gallons is going to be a simple cream ale of 6# 2 row, 2-3# minute rice, lightly hopped with hallertauer. If I was to add some carapils to the above grain bill to get some improved head retention, how much would you suggest?

Also, what is the high end of rice percentage in a grain bill?

 

[tagz]

For the Carapils, go less than a pound. For a light beer like a Cream Ale, I'd probably go 1/2 pound.