Did you also have a Plankton bloom ? cut off sunlight ? My baby pond weed and my Fanwort , both died way back ,5 weeks after adding 6 new GC . But, about a month after the GC my Secchi went from over 72" to 24" , beautiful medium green , GC may have helped , but thinking the bloom was the big difference. My Secchi Disk yesterday was back to 30" on the money.
