Aerators for Sale

Staff answers:

Aeration — the presence of dispersed air bubbles in the system’s hydraulic fluid. Aeration can result in severe erosion of pump components when the bubbles collapse as they suddenly encounter high pressure when entering the discharge area of the pump.

Cavitation — occurs when the pump is starved of hydraulic fluid. When this happens, air enters the pump and causes damage similar to that of aeration. Cavitation usually can be distinguished from aeration by the sound. Aeration produces an intermittent sound, whereas the sound of cavitation is more constant.

Cavitation means that cavities or bubbles are forming in the liquid that we’re pumping. These cavities form at the low pressure or suction side of the pump, causing several things to happen all at once:

The cavities or bubbles will collapse when they pass into the higher regions of pressure, causing noise, vibration, and damage to many of the components.

We experience a loss in capacity.
The pump can no longer build the same head (pressure)
The pump’s efficiency drops.

Cavitation occurs when:

NPSH A is less than NPSH R

NPSH A should be positive.

Edit:

Aeration often occurs simultaneously with cavitation.
Aeration occurs when excessive vacuum is created between the pump and the reservoir. This overcomes the integrity of seals and connections that have no apparent external leakage. Aeration may also occur when components have been worn or damaged and can no longer contain normal system vacuum. Under these conditions, outside air is pulled in and mixes with the oil. This creates a froth on the pressure side of the pump that lessens system efficiency and creates excessive noise as the air bubbles whistle past components in the system.

Staff answers:

Yes.
A pump would be great to aerate the water. Water can only absorb oxygen (air) from the surface. If you add a pump, it will circulate the water so that all of it makes contact with the air therefore making it more oxygen rich. Although some people thing air-stones add oxygen to the water the amount of air absorbed from bubbles is negligible. What the air stone really does is what the pump would do – circulate the water so it makes contact with the atmosphere.
Direct the pump towards an area that will prevent any “dead spots” – or areas that will not be affected by the movement of water so that ALL the water in the pond will be circulated or moved to the surface. I would also add a cage of some sort to the intake of the pump to prevent it from taking in any medium to large particles, like leaves. The smaller suspended material will pass through the pump without any problems.
It’s a good idea to have the pump situated so it keeps the surface ‘bumpy’ or like it had the tiniest of waves. Insects do not like landing on a surface that is moving up and down when they want to lay their eggs.
The surface of the pond should move as much as the surface of a swimming pool to prevent insects from landing – but that type of agitation is not needed for aeration. Less would be fine – as long as it is in constant motion.

Staff answers:

There are two kinds of aeration bing provided by this fountain system. All three heads will provide about the same amount of aeration based on pump size while the water is in the air, but an important additional amount of aeration is determined by how much rippling of the water surface is caused by the differing fountain head configurations.

The amount of rippling can also be changed by moving the head higher or lower or moving its location in the pond. Ripples are very significant in aeration because they increase the effective surface area of the pond and encourage water turnover from the bottom of the pond to the surface. Water that does not turn over is called stratified, and is divided into layers of different oxygen levels with the deepest having the least oxygen.