Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Initial Concentration and Target Concentration

I live on a lake that is 82 acres. We currently have 21.7 of EWM and are considering a whole lake treatment. Some of the information that was given to me was they would like to have a 0.375 PPM AE target whole lake concentration, however they will use 1.9 PPM AE to achieve this. How does one figure out that you must use 1.9 PPM AE to get to the 0.375 PPM AE?
Also, the 21.7 acres of EWM is 190.8 acre/feet, and based on the liquid 2,4-D calculation, it will require 260 gallons. The epilimnion extends down to 18 feet at this time. So really, I have a lot of the data, but I want to know how someone came up with using the 1.9 PPM to get the 0.375 PPM whole lake concentration?

While it is more expensive, I think you will see better long term control of EWM (2-3+ years vs. one year) if you use a Fluridone product in early spring before seeds are set that year. Dosage of that would be 10 PPB and a FAST Test done at 14 days to determine if an additional Fluridone "bump" would be warranted.

In small ponds I have had MUCH better control of EWM using Fluridone at 10 PPB then 2,4,-D.

To get the correct concentration you also need to know the % of active ingredient in the chemicals.

i.e. if you have 25% active ingredient in one gallon vs. 50% active ingredient in another gallon you need twice as much of the first chemical to equal the 2nd one. So, just going by gallons of chemical isn't quite correct.

62,172,375 gallons of water is your 190.8 Ac/Ft of water volume.

Are they calculating the whole lake volume, then calculating that they will need 1.9 PPM AE in the target area to achieve 0.375 PPM AE in the target area after it has dispersed throughout the whole lake volume?