Plants in the water do look like coontail. I would be interested in seeing the report of water testing. Send it to my email address listed the my profile. When water is collected during large amounts of plant growth it may not show many nutrients due to the large amount of plants have about all of the current amount of dissolved nutrients bound into plant matter. However those plants did not grow in lack of nutrients. Coontail often overwinters as green dormant plants which allows it to get growing early in spring before other warmer water species. One approach may be to use a herbicide early in spring (water temp 50-55-60F) and kill existing plants and new growth. Coontail regrows from winter buds so one should treatment to be a 2-3 yr project. Concern with this approach is, as best as possible, target just the coontail and not other beneficial competing plants that happen to be present. Treatment may need to be applied earlier than 55F before other plants are newly sprouting?. When most or all coontail is killed the FI and other nutrient absorbers should be in place to sequester nutrients. Once coontail is minimized the grass carp should be able to keep it trimmed to low or no density. When a pond has too many grass carp (GC) expect the clarity to be reduced likely around 14"-2.5 ft depending on number of GC. Reduced water clarity has a suppressive affect on rooted plant growth due to lack of light penetration which is not all bad for shallow weed-algae infested ponds.
I would regardless still contact Bruce Kania at FII and ask what density (sqft/acre) that he uses to sequester his eutrophic nutrient laden 6.5 ac pond. He uses a big fish harvest per year to remove bound nutrients. See Pond Boss Magazine Nov-Dec 2013 - Fish Fry Lake - A deeper testimony to using natural nutrients. He should at least communicate with you about your situation since you do already have some FI. He also has submerged weeds in his pond but I do not know the species nor the amount (% coverage and depth of growth).
I would at least get a quote for rebuilding the pond so you know how much money to budget for. Sooner or later it will have to be done regardless of who owns the pond. You are experiencing one of the big disadvantages of owning a pond that is too shallow and too big.
Last edited by Bill Cody; 11/29/13 09:03 PM.
