Good to see another member raising these guys. When my cyanurus morphed it was around 4 months after hatching. I had the water at only about 2 inches deep or less when they started to leave the water. I had tons of plastic plants and small cork islands in there to prevent drowning but still never allowed them to become completely dry or leave the water. After they all morphed and were eating fine I raised the water alittle bit every week until the ten gallon was 3/4 filled.
There is no caresheet for cyanurus as there is several races of the species which have not been truely measured. I used blackworms and chopped earthworms when feeding and they ate well. I kept the water warm, at around 70 - 72 degrees at all times even until a couple of months ago. I had these guys through winter which made me resort to a heater. I never had a problem with feeding, even when they morphed but I think keeping them wet and in water all the time is key.
I also had a difference in size between the larvae into morphing. I lost one large morph and one small one. Both seemed to have drown and I was not able to get them in time. The small one I believe was a runt and was basically a small picky eater throughout its life.
I assume you know of this basic care sheet
http://www.caudata.org/cc/articles/raising.shtm
I didnt really do anything different, changed the water daily with spring water, used chopped blackworms through larvae stage and beyound and kept it at a warm, steady temp.
If there are any other questions I can answer please feel free to ask. Good luck!
Mitch