Pond Boss Forums GENERAL QUESTIONS Water chemistry Managing phosphorus in a eutrophic pond

As the subject line says, I'm looking for suggestions on how to reduce the P level (or to bind it and make it un available to plants and algae) in a pond.

This specific pond has a high nutrient load due to trees and bushes growing up to the waters edge for a good 80% of the pond shoreline. Plus it is right next to, and on the downslope side of a nursery. There is no visible runoff into the pond, but.........

I am looking at 2 products, Phosloc by SePRO and The Solution by UltraClear .

The 2 products are applied differently, Phosloc is mixed into a slurry and distributed, The Solution is a granular product that is spread out over the pond surface.

After doing some reading, I'm wondering if spreading out Alum at the rate of 40# per ac/ft of water would do the same thing?

Rex, Bill, Bob, Nate, Greg or anybody else have any experience binding up P in a pond?

Scott, I would personally use the alum/hydrated lime at 40-60# alum and 50% by weight H lime per acre foot....I didn't see costs of the Phosloc but did notice there IS a toxicity level (just played down in literature) and the cost of ultraclear is much higher than alum/H lime.

Treating with an algaecide first would be a good idea as would broadcast spreading granular alum over the suspected watershed inflow area to bind new P entering the pond in future rain events and as an ongoing management program.

Minimal floc will occur at the 40-60# per acre foot rate, yet some floc may be desired as well....if desired, double the app rate.

Thanks Rex. Watershed is pretty much unpenetrable brush/trees. I doubt that any surface water is reaching the pond from the nursery. Pond has been treated with algacide already, visibility is 7' on secchi disk (disk laying on pond bottom in deepest part).

Along with what Rex says alum binds with phosphorus and produces a compound know as aluminum phosphate making the phosphorus unavailable. It was used on an Indiana lake by the INDNR a few years back with good results. Unfortunately I don't remember the name of the lake. I could find out if you want me to.

My thinking is these commercial products are nothing more than repackaged alum or a similar product and marked up in price; good ol' capitalism.

Here's some good reading on the subject:

http://www.marinebiochemists.com/phosarticle.html

https://www.soils.org/publications/jeq/pdfs/33/6/2040

So could something so simple as adding alum to a eutrophic pond really bind phosphorus and help to give me algae controll? Ive only heard of alum for clearing up murky water.

Yes.