Once they get around the 4-5" mark, molts are spaced out longer. My oldest (Na-na), 20+ years, is just under 6" and last molt was 17 months ago and is showing no signs of pre molt whatsoever. Bea-na is the youngest at 8. Eunice is the oldest G. rosea nearly 19 y.o.and 5 1/2", gained maybe 1/8" about a year ago and no signs of pre molt either.Wow...19 months! My G. roseas are both about that size. Now, I see I may have a whiiiiiiiiiile to go until they molt.