Reddit reviews VermiHut 5-Tray Worm Compost Bin, Dark Green with Free Worm-saver Tray

I got some red wigglers a couple months after starting my system. Was going to order some from Uncle Jim on Amazon but decided first to email the local USDA Ag Agent, asking him for advice on a local source. He provided an online introduction to a local gardener with a "worm lady" reputation. She gave me a shoebox full of "soil" with worms of every size and lots of cocoons or eggs. Decided to establish a colony in a separate worm bin. That was last spring. Reckon there are several thousand of them now. Once a week or so, when I take the lid off to feed them, I give a few to the fish and drop some into the growbed, a constant flood with Hydroton setup. Haven't seen evidence of an established colony in the growbed yet. As far as not drowning in highly oxygenated water, I don't measure oxygen levels but I know its higher in the fish tank than the growbed and they drown in the fish tank. Still, they might be able to establish themselves in that narrow band of pebbles near the water line. If your bed is "flood and drain" it will be easier for them.

That "worm lady" recommended a little book called Worms Eat My Garbage by Mary Appelhaf and Joanne Olszewski. I found it very helpful.

Nightcrawlers need to maintain deep vertical tunnels to the surface; a tall order in an aquaponic growbed.