The sugar and salt group did not grow at all. I've drained the container and filled it with dechlorinated tap water and moved it near a light.
The individuals I placed in different vases around the house are growing, and the one in my pond-vase with all the daphnia, scuds, hydra, etc. is getting really huge and looks to be budding. I think I'll be keeping nostoc in lit vases for now.