Why is Pond Aeration So Why is Pond Aeration So Beneficial?Beneficial?

By: Johnny Foster

Do you want this…Do you want this…

Or this?!Or this?!

Types of Systems VaryTypes of Systems Vary

Diffused Air Systems Fountains

Surface Aerators Circulators

Mixers

Injectors

Factors to ConsiderFactors to Consider

Objectives Pond purpose

Pond size

Pond depth

Pond shape

Power supply

Vegetation present

Existing water quality

Aesthetics and Appearance Aesthetics and Appearance ManagementManagement

Fountains with or without lighting

Aeration and circulation with pumps and/or compressed air

Ornamental plantings on shoreline or rafts

Docks and piers

Water Quality Improvement with Water Quality Improvement with AerationAeration

Can reduce undesirable concentrations of iron, manganese, hydrogen sulfide, carbon dioxide, ammonia and others associated with anaerobic conditions

Destratification reduces thermal/oxygen barriers to fish distribution

Algal biomass, species composition and growth rate are all affected by aeration

Destratification is Destratification is BIGBIG factor factor

From: Pentair/Aquatic Eco-Systems

Green Algal Plankton vs.Green Algal Plankton vs.Cyanobacteria Cyanobacteria (Blue-Green Algal Plankton)(Blue-Green Algal Plankton)

Green Algal Plankton Cyanobacteria Plankton

• Often beneficial and

desirable

• Produce oxygen

• Base of aquatic food chain

• Utilizes waste

• Removes pollutants

• Undesirable

• Ugly & Mean

• Smelly

• May be toxic

• Difficult to control

Aeration and Circulation May Limit Aeration and Circulation May Limit Cyanobacteria (Blue-Green Algae)Cyanobacteria (Blue-Green Algae)

Algal cells are physically re-distributed throughout water column

Solar energy needed for photosynthesis is reduced in deeper water

Mixing stirs up carbon dioxide and changes pH affecting species dominance

Ability to rise to surface may be disrupted

Changing hydrostatic pressure may kill some

Ability to use atmospheric nitrogen may be reduced

Large zooplankton can’t see to feed on green algae

System Design Affects Water Quality

Getting Dissolved Oxygen to the Getting Dissolved Oxygen to the Pond Bottom is ImportantPond Bottom is Important

Organic muck, which contributes recycled nutrients, gets consumed

Oxygen encourages phosphorus to bind to iron complexes in sediments

Oxygen allows bacteria, worms and insects to feed on organic muck. Fish feed on them.

Increased respiration on bottom produces more carbon dioxide, lowering pH favoring desirable diatoms and green algae

QUESTIONS?QUESTIONS?