under 1.75 wpg of strip tube lighting they have not really grown as suspected. Longest leaves have only been 12". not growing very thickly/bushy. roots insanely though. tried to move one, discovered a 18" runner coming from it that was shooting a new plant i hadn't noticed. There's no telling where their offspring will pop up. In this case, a LONG way away.
Considering cryptocorynes' reputation for melting away after moving, the spiralis plants in my tank have been shifted here and there (not in pots) and took it better than most of the other plants in the tank.
Occasionally, the tips of some leaves begin to rot but I just trim them away and that seems to do keep them from continued disintegration. I'm hoping that the leaves do grow longer seeing that it's potential size is quite impressive. The maximum length of any of its leaves seem to stop around 14" or so.
Lovely plant altho mine does not have those spirals in the leaves. Very fast grower.
The comment on earlier remark about moving crypts, I have never had a problem moving mine. Keep the lights and temp the same and move immediately and you won't have a problem. It's not the move they object to but the "change."
...wow, with lots of light (dual T-5 HO) and adequate fertilization, these guys go crazy! The plant displays its spiral characteristics under the brightest light; otherwise, it grows straight with lots of new sprouts; propagates like crazy with runners 6-10" from main plant.