Richard
I'd nuke it with Lime now with low water volume and remove all fish. Josh and I and maybe Steve and Condello can help you with that. Then we see if the water clears up. I'm hopeful this is due to high BH population keep bottom stirred up. If not, we do alum treatment until clay particles bind, fall to bottom, and water clears. Don't need to worry about exactly measurements with Alum since you have no fish to worry about. Easy.