Cactus / Ariocarpus seedlings

Ariocarpus are generally growing very slowly but if you could give a good condition, they will grow a reasonable speed.
I think the initial 3 years from germination may be critical time.
I do 1st repotting 1 year after the germination. You will lose some seedlings at that time but the growing speed will be accelerated after the repotting.
The photo is Ariocarpus retusus v elongatus, sown seed on 23/09/2011, in a 10 cm square pot.
I will repot them next September.