Succulent seedlings: hoodias and cacti

The Hoodia gordonii are growing steadily although it seems that they weren't getting enough light so I moved them across the room because the sun's angle has shifted considerably as winter approaches. They are growing a little better with better light and I am still watering them although I will need to be careful to stop watering them once the temperature drops much lower. They need to be kept fairly dry over winter. I have 47 little plants in total.

I still have no idea what cacti have germinated here although the little red lines on the left-hand seedling suggest that its a different type to the one that has turned purple. I still suspect that the purple seedlings are an invasive form of Opuntia or something, especially since these seeds germinated after more than 5 years although it's mostly one type of seed that germinated from the mixed seed packet.

First posted here on my blog in WeKu