I've had the big one (around 25cm) for a bit over 3 years now,got it at about 4cm. He's really unstable (redish substrate is an experiment to try help that) and is usually mostly dark grey but I still love him!!
The other two I got within the last 6 months, and they've bulked up heaps being fed on shrimp. The smallest is about 8cm and the other is about 14cm.
The tank is 120x50x50, but I'm setting up a 150x70x60 in the garage to house the dats, bichir, flagtail, uarus and a few catfish (nothing exciting, just a couple of syno's and raphaels, we don't get any big catfish here). The loaches (8 around 10-15cm) will stay in the 80g along with some heckelii's and geophagus I'm growing out in a smaller tank, and more loaches!!!!