Pond Boss Forums AERATION Should I aerate? Aeration?

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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