I got them about a month and a half ago. I went with the small “Sea Monkeys in the City” tank. They’ve got quite big now, but their water is low and I think many of them may be pregnant…they have these little sacks or something attatched to their mid-sections. What do I do? Can I just use regular water–I don’t have any of that powder that I put in the water with the kit. How do I take care of them now? Do they need a bigger tank? Help?!?