Pond Boss
Posted By: Texasbikers Aeration with high phosphorus ? - 04/11/22 10:55 PM
Hi, we have a new pond completed in October, really it's a old pond we pumped dry, dug it all up, new dam and key, compacted, bentonite used and it finally does not leak. It's just shy of an acre, no natural spring, rain from the sky and runoff from three hills around us keep it full, It was two 18" overflow tubes to control the level. It kind of like a pool, has a shallow end then progresses deeper to 10-12 feet.

I'm outside of Nashville in Smyrna TN, I called a local Pond company to inquire about fish stocking. Our primary use will be to fish it for fun and to look at it from our front porch. The Local Pond company rep talked to me about fish, I feel good there.

I asked about Aeration telling him I was going to do a bottom bubbler, he advised against that because with the soil type we have in middle TN, largely clay, the Phosphorus levels are very high. So high that they won't do plants or install plants in ponds around here. And, he said to use a surface aerator to get oxygen into the water and help with Algae management.

I'd not heard this before so I wanted to put it out there. Thoughts and opinions welcome! Thank you!

PS. We have 120v 20 amp service at the pond available.
Posted By: esshup Re: Aeration with high phosphorus ? - 04/17/22 04:41 AM
What you were told is news to me. Never heard that before.
Posted By: Snipe Re: Aeration with high phosphorus ? - 04/17/22 05:10 AM
If phos is high then you NEED plants to convert it so algae growth is minimized.
Surface aeration is used commonly in high intensity propagation but not sure it's "better" than diffuser type bottom aeration? Under normal capacities, 10-20% aquatic vegetation of the right types can eliminate dissolved oxygen issues for the most part, under good conditions.
Posted By: Bill Cody Re: Aeration with high phosphorus ? - 04/17/22 08:34 PM
Aeration of the deep water actually keeps the sediment better oxygenated to help bind phosphorus to the sediment - silt. Read the science of phosphorus in soil.
Soil Mineral Type
Clay Content
• As the amount of clay in the soil increases, absorption capacity
increases as well. Clay particles have a large amount of surface
area where phosphate absorption and binding can take place.
Abstract from SCIENCE • 4 Oct 1974 • Vol 186, Issue 4158 • pp. 53-55 Anaerobic soils released more phosphate to soil solutions low in soluble phosphate and absorbed more phosphate from soil solutions high in soluble phosphate than did aerobic soils. The difference in behavior of phosphate under aerobic and anaerobic conditions is attributed to the change brought about in ferric oxyhydroxide by soil reduction. The probably greater surface area of the gel-like reduced ferrous compounds in an anaerobic soil results in more soil phosphate being solubilized where solution phosphate is low and more solution phosphate being absorbed where solution phosphate is high.

I would ask the local pond rep for some sort of published scientific proof of what all he is saying. Surface aeration will not to my knowledge deter algae any better than bottom aeration. Actually surface aeration alone in a stratified pond allows the sediments to go anoxic and then decay releases phosphorus to grow more algae. Read the science literature.

If phosphorus concentrations are high in pond water how does the local pond rep propose to reduce P concentrations?? . P always encourages plant growth so how does he propose to reduce excess plants?. Science says plants use and bind P and nitrogen for growth so if there are no submerged plants and these nutrients are abundant what keeps the problematic algae from being overabundant?. It sure won't be aeration.

What fish stocking plan is this guy proposing?. Do we assume that he sells fish also?

Be leery of what this guy tells you and always get a 2nd opinion. IMO you should look for a better educated pond rep.
Posted By: esshup Re: Aeration with high phosphorus ? - 04/18/22 03:40 AM
Well said Bill!!
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