Many fish farmers assume winter means aeration can be switched off. In fact, an aerator still plays an important role in cold weather - but for a different reason than in summer. Around early November to early December, most ponds in our region have little actual oxygen demand, yet experienced farmers keep running the aerator. Here is what they know and how to use it correctly in winter.
Why run the aerator in winter?
The aerator in winter is not mainly for adding oxygen. A small part of the benefit is oxygenation, but the main purpose is to balance the temperature between the surface layer and the bottom water.
In winter the surface water can reach 10-15 degrees or higher, but 30-40 cm below the surface the temperature is still very low. Without circulation, the cold, dense bottom water stays at the bottom and the warm surface layer stays on top - a sharp temperature stratification that stresses the fish and slows their feeding.
Running the aerator mixes the upper and lower water so the whole pond warms evenly. This matters because we still feed the fish in winter - the goal is to keep the fish from losing condition ("falling off in weight"). Once the water temperature rises after aeration, the fish feed more eagerly, and the feed conversion ratio is also a little lower. In short, winter aeration = temperature balancing + steady feeding + lower feed cost.
Why turn the aerator off when feeding?
This is a key point based on several years of farming experience. In winter, fish naturally have a low appetite. If the aerator keeps running during feeding, the water movement often directly scares the fish away from the feed - the fish simply sink down and stop feeding. So when you spread feed in winter, switch the aerator off first and let the fish feed calmly in still water; restart the aerator after feeding is finished.
Winter aeration tips in short:
1. Run the aerator mainly to balance surface and bottom water temperature, not just to add oxygen.
2. Feed only after the water has warmed up through aeration, so the fish eat better and use less feed per kilo of growth.
3. Always switch the aerator off during feeding in winter - moving water suppresses the already low winter appetite.
4. Choose a quiet, low-maintenance aerator for cold-weather operation; a roots blower with bottom aeration pipes works well for temperature mixing without excessive surface disturbance.
Jiangyin Zhongxin Machinery — one-stop aeration solutions. Contact: +86 180 1341 8091 / +86 180 1341 8097 (WhatsApp / WeChat).
