I absolutely love this setup and may emulate it down the road. I wouldn't call it a true ecosphere in the sense that the name was coined by the commercial product, since you do feed the shrimp. Have you considered not feeding them for a couple of weeks to see if it's self-sustaining?
Thanks! Yea, I just thought it looked like a giant ecosphere without being closed at the top. They can go for a long time without me feeding them but I want them to breed so was hoping that occasional feeding would help. It wouldn't be self sustaining unless I sealed the top since I have to top the water off about every week or so.