My tank has been up for only 3 weeks now... similar situation with half cured rock, and half was cured in the tank for 6 weeks prior. I used some iodide (5ml, twice a week, which is less than the recommended dose) during the cycling process and for the past 3 weeks... I've had a lot of additional corraline algae growth on the cured rock, my kenya tree doubled in size, as have the mushrooms. The uncured rock is just starting to see the tiniest specks of purple showing up. For me I had 80lb of cured LR
with already existing coraline algae, and 40lb uncured.