One of my zebra danios has disappeared. He's been gone for a few days and I fear he's dead and stuck somewhere in the plastic plants or decorations in my 55g tank since he hasn't floated to the top or been drawn to the filter intake. Ammonia has also risen from 0 to 0.25, which I guess is due to his decaying. Since he's such a small fish, is it necessary to find and remove him or is it safe to let him decay naturally? Doing a full search would mean a lot of disruption to the tank and I'm worried about the stress that would cause his tankmates.
