Not an expert on fluridone, but I got interested in it last year when there were two or three members who had fish kills after using it. Didn't make sense, as it's so nontoxic for animals. What I found out:
1] Fluridone is dependent upon sunlight for destruction of chlorophyl, so you might not want to use aquashade, unless everything you want to kill is on the surface or immediately below.
2] It works by destroying chlorophyl, which eventually leads the plant to die. However, the plant will continue to produce energy by oxidative phosphorylation of stored carbohydrates--that is, consume oxygen through the process of respiration. At times in which DO is relatively low, during the warmest water temps and/or when biomass is high, the reduced 02 production from loss of chlorophyl coupled with increased oxygen uptake by the plants can definitely precipitate a fatal event.
Hope this helps.
