Ok.
I have LdL = 3.19x10^-8*dt
∫LdL ==> L^2 / 2 = 3.19x10^-8 *t + C
at time = 0, L = 1.7617m
1.7617^2 / 2 = 0 + C ===> 1.55179 = C
at time = t, L = 2.0604m
2.0604^2 / 2 = 3.19x10^-8t + 1.55179
t = 17,894,377s ==> 4970.66 hours <-- time it takes to get another foot of ice ...