I recently just picked up this model of air pump of craigslist, it seems like it’s gonna be way bigger than I need. If anyone has a pump for around 20-30 tanks they’d like to trade+$ for this pump let me know. Can also sell it for 80.
I'd be surprised if that was too big for 20-30 tanks, you might want to test it first, but the manifold looks like it might be designed for less. If you have deep tanks, it would probably need to be oversized, but if they're all small tanks, then its possible.