Brian:
Hope you read this soon. You sound as though you are on the brink of a fish-kill.
Water temperatures are high in Central Texas right now. Water loses its capacity to hold dissolved oxygen when that happens.
You also say you have well in excess of 200 head in your one-third acre pond. Eeesh.
Most any fisheries biologist would say the D.O. problem in your one-third acre pond is accelerated by overcrowded fish. Without an aerator, you're trying to carry too many fish for the tiny system to support.
The third element working against your success is the aquatic vegetation. Just as those weeds add oxygen to the water, they also take it away.
Fish gulping on the surface is a bad, bad sign. Hope they survive through the night.
ASAP, suggest you add an aerator or remove some fish. Otherwise, Mother Nature is about to remove them for you.
Mark McDonald
Editor, Pond Boss
