Jacklyn I'm your neighbor, just over in Winston-Salem! I bought them at 2.5" from Hans so my guess is it's due to something I am doing. I've learned several tips where, if I had been doing those things from the get go, would have aided in much more rapid growth. Oh well, you live and learn!
I haven't fed them either of the worms you just mentioned since making the turkey burger recipe so I'll give it a shot! They eat like savages so luckily they eat the flakes I have (I probably feed them a meal of that every 2 to 3 days).
But yes, the more I am learning the more I realize I do seem to be quite fortunate with my water parameters! What are your parameters over in Greensboro?