Wow these are incredible pieces of large E. Bambusa. At one point I worked in a fish hatchery in Highschool up here in Massachusetts, they hatched, bred, and kept Atlantic salmon at the time. Since Yellowcheeks entered the trade around the time I worked there in 2010/2011, I always thought they would have grown and lived well in the enclosures we kept the salmon in. Those enclosures seem to be somewhat similar to the pond you have these in. They were round concrete pools with a pump that pumped TONS of cold water at them 24/7. Some of the males got enormous, I'd get fishing waiters on and get in to scrub the enclosure and they'd swim right through your legs. Too old, tired, and monstrous to be bothered by me much. I wonder if down the line you'd be able to enjoy the same leisure time with your Yellowcheeks. These are by far the best ones I've seen over the last decade. I'll scroll back in the comments to find out how your success came to be!