Pond Boss Forums Thread Like Summary - Aeration?

I am looking for advice on adding aeration to my farm pond. The pond sits in front on our family home so I will be able to trench electricity from the house, around 250 feet. There are fish in the pond but my main concern is the algae that covers the pond every summer. For years I have tried chemicals and even had a pond management company do monthly applications. I do not live there so it is hard for me to keep up regular spraying. So my hope is aeration will help with the algae problem at least to the point that not as much spraying will be needed. In the winter the pond is 1.5 acres and 8 feet deep at the overflow pipe. It does leak, not through the dam, but this area has a lot of limestone caves, so most experts believe that is the cause. It is full in the winter but can go down to half that size in the summer. I cannot afford to fix it but would be happy with the amount of water if it could remain clean. So will aeration help? The closest installer of aeration is three to five hours away. I have four quotes with different types of aeration, AirMax, Vertex and AerMaster Elite. Most propose three head diffusers, one with four, combinations of deep and shallow water. Is it necessary to run them 24/7? How much maintenance is required on an ongoing basis? I am not there all the time, so what happens if the power goes out? Since the pond leaks and the depth will vary, will there be problems if the water becomes too shallow above the diffusers, is that a problem? Sorry for the length of the question, any suggestions are appreciated.

In My Educated Opinion.

1. Are you feeding the fish? If yes, stop and harvest as many fish as you can to reduce the fish biomass because then you are no longer providing fish welfare food. Feeding fish adds lots of fish manure nutrients from more fish than the pond can support naturally. When feeding the fish the pond is an animal feed lot that produces excess nutrients. Nutrients grow plants. Nature’s law.

2. What do you think is the biggest bass in the pond? Big bass eat bigger stocked tilapia. This means more expense of buying bigger tilapia to survive predation for algae control.

3. Grass carp rarely eat very much filamentous algae. Sometimes they will eat duckweed but IMO usually not much duckweed unless it is the only plant. The big algae and duckweed consumers are the tilapia who are primary vegetarians. As mentioned they need to be stocked each year. BUT also chemicals need to be added each year thus chemicals are also a big expense plus algaecides and herbicides chemicalize the pond, often with ‘unhealthy’ stufff for the pond habitat-ecology. Tilapia is an expense but it is mostly no chemical, very good algae control IF ENOUGH TILAPIA ARE ADDED per acre and depending on how much algae needs to be consumed. Each fish can only eat just so much. More algae requires more tilapia, just as more plants require more chemical applied for control.

4. Israeli carp are basically a sparsely scaled strain of the common carp (common German carp). Koi are the same specie. This specie of carp have taste barbells on the side of the mouth. The Israeli and Koi are promoted by some fish farms for algae control. I studied this concept in detail. Their diet is minimal algae and preferred are mostly bottom dwelling invertebrates. They are omnivores eating living and dead stuff. Most of the small amount of plants consumed are accidentally ingested in the fish’s sediment rooting search for invertebrates and worms that live in the bottom mud.

Watch a carp feed. It roots and digs up to its eyes in the bottom mud sucking up and straining out mostly animal goodies as it digs and works through the sediment. Junk & sediment passes out the gills. The bottom feeding process causes re-suspension of sediments and mud making the water cloudy with fine sediment. The more Israeli, koi, and common carp one has the more muddy the water becomes.
Aeration currents help keep the mud and fine sediments in suspension. Plants grow poorly in muddy murky water. This process is how Israeli carp, koi and common carp control algae and plants by making the water turbid so plants receive less light and do not grow very well. Israeli, and koi and common carp really are not eating the plants / algae compared to tilapia who actually eat and digest lots of algae and delicate plants for their growth. The carp’s rooting / bottom feeding disruption keeps plants and algae from becoming established on the bottom. These carp fish can help to control algae if you don’t mind muddy roiled water. Pond dye makes the muddy water look blue as in “Make-up on a pig”.
Grass carp aka White amur are vegetarians and they, same as tilapia, eat and digest the plants that are normally picked, snipped, or sucked up separate from the bottom. They usually work up off the bottom not digging in the bottom. When plants are gone tilapia can eat and digest organic bottom materials even better than carps.

5. Your picture shows evergreens blocking wind action on one side of the pond. Usually natural wind action will mix pond water down to 6ft deep. Water deeper than 6ft is the area or volume that needs IMO to be artificially mixed to keep oxygenated water on the deep bottom areas for good, rapid organic muck decomposition. Bottom aeration is for maintaining oxygen on the bottom helping to make the bottom sediment more ‘healthy’. Oxygen using bacteria thrive by decomposing dead organic material converting them to nutrients for reuse by plants. Algae if growing on the bottom of the pond in deep water, also adds oxygen to the bottom zone. ALL filamentous algae always starts growth on the bottom or attached to underwater surfaces. Murky, cloudy water does not allow plants to grow well in deep water. IMO you only need to aerate the bottom areas deeper than 6ft which may require only one or maybe two diffusers to pump and lift the bad DEEPEST water out and up to the surface where it then gets oxygenated and degassed. Ample oxygenated water on the bottom in the deep zone from bottom aeration has MANY benefits but algae control is not one of them IMO and professional experience.

6. Try this. If the pond companies are saying aeration will stop and significantly hinder algae growth,,,, ASK them if they will guarantee their aerator will significantly do this or your money back. I know the answer. They will say yes when combined with using their chemical plan. The chemicals are controlling the algae not the aerator. I tell people that have a small pond and if you add 2 to 4 cups of fertilizer to the pond even 6-10 aerators will not stop the algae growth.

7. Asked - “necessary to run them 24/7? How much maintenance is required on an ongoing basis?” IMO in 8 ft max depth there is not a lot of water volume to get moved out of the deep zone. Thus running 24/7 would not be absolutely necessary HOWEVER it could be very beneficial to help digest the muck sludge in the bottom PROVIDING if the deep zone in summer loses its dissolved oxygen which may not actually happen if the maximum depth is only 4-5ft (1/2 of 8ft maximum summer low level). Dissolved oxygen (DO) testing would verify DO amount mid-summer on the bottom. IMO diffusers should not be any shallower than 5 or 6 ft during maximum depths due to the summer low pool and natural oxygenation mostly by plants in shallow water.
Most all bottom diffuser Aerators only need annual maintenance of checking the compressor, cleaning / replacing air filters and cleaning the diffusers. Since you are not there 24/7, I fear vandals and trespassers could damage or steal the compressor/aerator and cabinet. It is worth stealing! Plus with only 4-5 ft of water in the summer, and nature with its average wind mixing should usually keep the bottom zone oxygenated due to sunlight penetration IF water clarity is 2ft as measured with a white coffee cup or 6”-8” dia plastic lid on stick or a cord, aka DYI secchi disk.

8. Your pond problems are a symptom of the problem. Excess filamentous algae and duckweed are indicators of excess bottom muck and over enriched plant nutrients in the pond. This always happens in old, aging, very nutrient rich ponds. Ponds are natural collection basins with no drain. Nutrient enrichment grows more plants. Nature demands it. When I see these problems to excess, I always strongly suggest a pond clean-out and rebuild to get rid of all the nutrient enriched bottom sludge and deepen the shallow areas. Deepen and repack the pond bottom properly so it does not leak. A pond rebirth is needed. Maybe even down size the pond to ½ or more of the size if money is a problem.

9. I guarantee if you put enough tilapia in, they will do the job of eliminating the algae. They are nature’s algae eating machines, but you need to buy more each year. Bass do eat lots of small and baby tilapia especially if bass are big and/or overpopulated. As mentioned earlier you might consider killing or renovating the pond of fish. Start over with just tilapia each year. They are a great sport fish for kids and in early fall catch them and eat some of the large 12"-14" tilapia that cn grow in VA. New baby tilapia are the algae eating army. If bass are eating lots of baby & small tilapia more big tilapia at stocking need to be added to increase the “algae army”. Around 100 small 3”-4” tilapia last summer completely denuded my 0.6 ac of algae & Chara filled pond that has no bass.

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The water clarity shown in the picture indicates to me the filamentous algae(FA) grows on the bottom down to around 5 maybe 6ft deep. Thus all pond bottom areas less than 6ft will produce your algae growths that eventually break loose and float. Once floating those floating clumps are basically done growing and waiting to die due to some reason and sink, then hopefully they decay and or create lots of bottom muck. New appearances of FA are always from more mats breaking loose from the bottom.

Cause of the algae growth is due to excess nutrients in the water that are not being consumed by other plants. If the pond had lots of submerged plants to use the nutrients, water would be very clear and weed infested. The more nutrients that present the more plants that will grow to use those nutrients. Nature demands some sort plant grow to use available nutrients. Nature has thousands of different pant species available to grow in all sorts of nutrient enriched conditions.

Filamentous algae(FA) grows because more dissolved nutrients are available than being used by all other forms of plants that are present. Tree leaf litter entering the pond each year contributes lots of dead nutrient laden material that when decomposed releases those nutrients. Natures policy. Waterfowl manure also adds lots of nutrients. 10 geese make the equivalent manure of one cow. Geese are FLYING TOILETS.

When one uses pond dye its purpose is to reduce sunlight penetration. Reduced light from dye if used properly reduces the amount of algae that grows in water deeper than 2ft. The water needs to be around 2ft deep and dye dark enough to filter enough light to suppress algae growing on the bottom. As per label the concentration of dye should be around 1 part per million. This, when using the gallon container size, is same as one gallon per million gallons of pond water. If less dye is used then less algae or fewer rooted plants will be suppressed. FA growing deeper than 2-3ft is a good indication the dye concentration is not dark enough. A little bit of dye should be added monthly to adequately compensate for: dye evaporation, dilution, UV fading, chemical decay, and absorption into sediment and organics. Dye is an organic stain. It naturally and gradually breaks down and dissipates. I recommend the small monthly amount be applied in Nov-Dec and again as soon as ice melts in spring and also monthly. Monthly dose is 1/10 or 1/12 of the original volume treatment. Remember dye is used for pre-emergent treatment for plants. Dye does not kill the plants.

Filamentous algae always starts growing attached to the bottom or on solid structures wherever it receives enough light for growing. Thus dye should be best used before the algae is growing i.e. as a pre-emergent. It does not control floating algae mats, already well established bottom FA and submerged plants, or emergent (shoreline) vegetation. Floating FA is best removed or treated with an algaecide. Heavy hard rains, strong waves often beat-up the floating FA and it sinks.

FA of one species or another is usually a continual problem in shallow areas of ponds. Often FA does not grow in the deeper central bottom area of ponds due to lack of adequate sunlight. Tilapia are the sheep and goats of the pasture keeping the FA trimmed and eaten.