As it just so happens I live on a creek! I have to navigate a very small forest to get there and see if it is running (this is Arizona after all!) If I can find a good rock I will add that
I will stop adding the AL as often (I stopped using it for about 3 weeks in the middle of this to allow it to cycle, and only started again when the fish were hiding a lot) to check the ammonia again. I know that the AL can effect the readings. They don't seem to be hiding as much now so hopefully it will go well. And Plato the Pleco seems to be doing okay, which I take as a good sign.
Thanks so much for your help!