Help.. The lone survivor tiger shrimp in my tank started to stand off balance recently. It appears to be fine, still eating and moving around. My amanos and bamboo shrimp are doing just fine; in fact my bamboo just molted 5 minutes ago, the two amanos are eating its shell right now. I recently introduced fluval shrimp stratum into the tank(because I plan to introduce CRS in about 10-15 days). no2, no3 are both almost zero, and that means ammonia is also zero. I'm observing algae growth in my tank, which in my experience means the nitrogen cycle is still intact.

Any ideas guys?? Help....