A: Lack of oxygen is a main cause of poor water quality, quickly turning ponds and lakes into foul-smelling pits that support little if any wildlife. Aeration will break up still water and add dissolved oxygen to improve the quality of water and deter excessive algae growth. And it does that without having to resort to chemicals. It's an environmentally friendly and cost-effective way to maintain well oxygenated water that is the basis of a healthy ecosystem.
A leading brand of water aeration kit for lakes and large ponds is Otterbine. It is supplied in the UK by Lely (UK) of St Neots. The company offers three types of Otterbine aeration systems. The type most suitable for your facility will depend on the depth of water.
Surface spray systems are ideal for aeration and vertical circulation in lakes less than 4.6m deep. By mixing surface and bottom waters, surface sprays break up the thermal stratification associated with still water. This system creates convection patterns that break up mats and clumps of algae.
The second type is the horizontal aspirator. These are suited to lakes ranging from 90cm to 3.6m deep that will benefit from a strong directional flow. The aspirators create artificial currents and break up algae mats in stagnant water.
The third system is called air diffusion. This is where an on-shore air compressor or compressors pump air to diffuser manifolds at the bottom of the pond or lake. It is the preferred method for water greater than 4.6m in depth but can also work in water as shallow as 1.2m. However, any bottom diffuser loses roughly 50 per cent of its aeration and mixing capacity for every 90cm increment of depth shallower than 4.6m.
- Sally Drury has reported for HW and its forerunner GC&HTJ for 27 years and has spent more than five years testing machinery for HW and What Kit? The advice in this helpline is independent.