You should have also tested for NH4 (Ammonium). The other results seem OK except for the NO3 (Nitrate). I can't believe that you show a '0' reading for this compound. The complete absence of Nitrate in an aquatic environment is very rare in even heavily filtered & planted lined ponds, and practically unheard of in an earth-bottom. Just the normal run-off from rain and/or irrigation will create an organic load in the water column. I would definitely test for Ammonia and retest for NO2 and NO3 in about 4 weeks. Check the expiration dates on the Test Strips.
Muck is normal in an earth-bottom, not usually a problem causer.
Turbid water can be easily cleared with Gypsum.