That's what I ended up doing. It took me 2 attempts though. apparently they don't do very well when shipped! I have been running a culture for a couple of weeks now. Also starting a Grindal worm culture as well. So far so good Thanks for the advise though.
Right now I have a 2.5 gallon tank that I use as a snail farm for my puffers. It has tons of ramshorns, a few neocardinas, and that's about it. Every few days I drop some algae wafers, maybe some Ken's veggie sticks, or some flake into the little tank and they snails are just exploding and sustained for months. I do a 90% water change 1x each month and that's it.
There's an assortment of live plants in there, and I always have some of them in a state of decay, to try and keep the water full of microbes and rotting plants, which seems to work. It actually stays incredibly clean in there!
I am starting to wonder what might happen if I were to just throw some daphnia in there. With nothing to eat them, I wonder if I coudld keep them going!
Not sure what the outcome would be but they constantly eat what ever is floating in the water column. I feed mine a mix of spirulina powder and activated yeast. Also, snails require calcium as so do the daphnia. Snails will use up most of the calcium in the water for their shells and leave the daphnia with not enough for their own carapace. I read that daphnia tend to do poorly with snails because of this... Again, just something I read.
Daphnia are cheap and you only need a small number of them to get a colony started so why not experiment!