Seeing how quick to breed my duospilus were once my dominant male had his own territory, I decided to upgrade their digs. I'm getting 4 F1 Rhinogobius rubromaculatus who will join my duospilus 6 very shortly. I only had a 29 available for them, and I felt like I would be wasting most of the space it affords, so I got a little creative. These martini glasses have a 9" diameter and were $6 from Michael's. Essentially, I've subtracted 3 square inches from the bottom, and added 190 square inches of "floor" space available for territory (that's my math, anyway. 4.5 squaredx3.14 for each, right?). They already are using it, though so far no males have claimed a glass for their territory. They simply haven't needed to yet, though that will change when the rubros come and if my eggs grow up into little gobies! This is a little bit of a departure from my usual naturalistic scapes, but, well... at least I didn't use pink sand and name the tank "Sex in the City" as my wife suggested. Specs are: 29g, stock lighting, Fluval 105, No heater. The father of my eggs: This is the prime cave. My two biggest males have sparred over it a few times. The above guy has it for now, and I think he'll keep it. There's a little female in the pvc cave below And up on her glass. It's always this one. I think females like their own territory too.