Sounds like you may be aware of a stagnating water body nearby.
Stagnating water bodies are characterized by the presence of algae & aquatic weed growth and noticeable muck levels at and near the shoreline. Stagnant water also stinks and is not pleasant to swim in or look at. Stagnating retention ponds or lakes are an even bigger problem for those who live directly next to a retention pond or lake. See blog title The Health Risks Associated with Stagnating Water in Your Backyard or Municipality.
What Can Be Done?
Start at the root cause, depleted dissolved oxygen (DO) levels.
Stagnant water is in decline because there is not enough dissolved oxygen in the water to sustain the type of bacteria required to maintain a healthy and vibrant pond or lake. This usually happens because your water body is not moving or at the very best moving slowly. Water that doesn’t move much or at all starts to develop warm spots on the top of the water and cooler spots at the bottom. As the summer starts to heat up these differences in temperature are more prominent and a sharp thermocline starts to develop within the water body where the deepest water is colder and anaerobic (see fig. 1). The anaerobic bacteria that live at the bottom of the lake are the ones that release odorous gasses and cause your pond to stink. Refer to our article entitled Dissolved Oxygen (DO) is the Most Important Thing You Need to Know.
Low DO in your retention pond, dugout or lake will eventually lead to the death of fish, frogs, crayfish and more. Low DO or anerobic conditions will reduce the beneficial bacteria that consumes the extra nutrients floating in your water creating muck. More muck along the lake bed and along the shoreline creates the perfect bed for aquatic weeds! As your water body gets cloudier from muddy bottoms, you will see the formation of green algae on the surface of your once beautiful water body.
Can You Increase the DO Levels In Your Water Body?
Simple answer… yes you can!
Water aeration treatments are widely documented as viable solutions for reversing the adverse effects of stagnating water. Water aeration is simply the process of adding diffused oxygen to water.
How Can You Aerate Your Own Water Body?
Water aeration is most effective when the oxygen-rich air is supplied directly to the bottom of your lake or retention pond. By applying oxygen to the bottom of the pond, you remove the thermocline and activate the bacteria you want working for you. Simultaneously, you remove the anaerobic-loving organisms from the lake that produce nasty things like blue-green algae.
In stagnant water bodies a thermocline develops towards the bottom. Water below the thermocline is colder and anoxic in comparison to the water above the thermocline. By applying oxygen to the bottom of the pond, you remove the thermocline and activate the bacteria you want working for you.
Types of Aeration
- Floating fountain (surface aeration, not recommended for water bodies deeper than 4 feet)
- Floating fountains only circulate water within its vicinity and doesn’t go very deep. For shallow ponds, a couple of well placed floating fountains can effectively aerate your water and dramatically improve your water body. When your water body is deeper, the enriched oxygen doesn’t penetrate the first thermocline and thereby doesn’t activate the bacteria required to eat the extra nutrient load in the water, resulting in a pond that will continue to deteriorate. See blog titled The Fallacy of the Floating Fountain. Expensive to operate, plugs up if the water is not clear… best used as aesthetics on treated ponds.
- Coarse bubble aeration (sub surface aeration, expensive to purchase, expensive to operate and extremely noisy)
- Coarse bubble aeration is one form of sub surface aeration that has been routinely used in lakes and large water bodies for years. Widely recognized as superior to most methods has been the method of choice as it effectively gets oxygen beneath the thermocline. The drawback for coarse bubble aeration has been the initial costs including the cost of the equipment and freight, the incredible noise the compressor makes (similar to a jet engine) and the cost to operate (up to $4000/month for each compressor in the coldest months of winter).
- Fine bubble aeration (sub surface aeration and the now widely recognized method for increasing DO levels in stagnating water bodies)
- Fine bubble aeration is relatively new and is now taking over as the number one aeration treatment for stagnating water bodies of all types (ponds, storm drainage systems, farm dugouts, lagoons and lakes). Subsurface oxygen is pumped into the bottom of the water body via small and efficient compressors to special diffuser plates that create extremely fine air bubbles. For a number of reasons this is superior system. The equipment itself is easier to handle, less expensive to purchase and doesn’t use nearly the electricity the coarse bubble compressors use. Moreover, the fine air bubbles are more efficient at bringing up the concentration of oxygen in the water and especially below the thermocline vs. larger bubbles that don’t have the surface.