It surprises me that such a short downtime would cause a fish kill, but my pond being only 3 years old has never developed a stink either. My pond is shut of every day from mid morning to late evening, but once again...it's a young pond.

All things considered, it would be safer to bring it back up slow rather than all at once I would think given this recent fish kill. Hopefully someone with old pond experience will chime in soon.

How many pounds of fish do you think you have in the pond?

Fish on!,
Noel