We have traveled the world touring shrimp farms and have seen all kinds of types of aerators at different shrimp farms. Electric, diesel, plastic, metal. In this post we want to share what we’ve learned and what you should look for when looking for new aerators for your shrimp farm.
Why is aeration important?
Aeration in a shrimp farm is important for a few key reasons:
- It keeps dissolved oxygen up during the night after photosynthesis stops. By lifting the top of the water column into the air and spraying it, it introduces additional oxygen molecules into between the water ones, thus keeping DO levels at safe levels.
- It allows higher stocking densities. Not only do aerators allow to stock shrimp at higher densities more safely because of higher dissolved oxygen, but without that higher DO, shrimp will not digest food nearly as effectively, leading to an unfortunate jump in FCR.
- Finally, for ponds with an internal sludge drainage system, an aeration system can create a current that will slowly syphon the solids into the middle of the pond and out to an effluent holding tank
Electric or Diesel?
This really depends on the electricity available on the farm. From a sustainability standpoint, electric is far better because the electricity can be generated by greener sources. Similarly, if you are looking to automate aeration, it is simpler to build in automation into an electronic system, rather than build relays in a diesel one. It’s possible with diesel, just more complicated.
The flipside of this, is that electrical systems can be less stable. Lightning can strike nearby power lines and take the whole system down, etc.
Other Things to Lookout for:
- Quality of the motor: This is a major one. We’ve heard from many farmers who bought cheaper paddlewheels only to end up spending way more money servicing them after the motors have broken and needed repairing. The investment in a higher quality motor tends to payoff.
- Paddlewheel design: We haven’t seen that much variation in overall paddlewheel design from one to another but they are slight. Read the specs, ask to speak with other farmers who have bought them and see how the rated HP of the aerator actually translates into aeration.
- Quality of the plastic: Again, this comes down to price. Cheap plastic will degrade faster in the water and the strong sunlight. If you are investing in an aerator invest in one that lasts.
- Complex gear mechanics: We’ve also seen in smaller farms using a single motor and a complex set of gears to spin multiple paddlewheels. This loses money overtime vs. using multiple motors because of the energy lost in each set of gears. You are better off investing more up front for more motors. You’ll save money overall and use less energy.
If you are looking to buy new paddlewheels or aerators for your shrimp farm shop around. Ask questions. Ask your friends what works for them and invest in something that will last.