Alright. I will try to answer all questions. Been doing water changes (I hour on, 1 hour off) all day. I am on a well. I cleaned out my filters and added lots of Prime! Skimmed all I could off the surface with nets. I will continue water changes tomorrow. Fish seem to be fine and eating well. I have some MediKoi on hand, so I fed that today just to boost their immune systems a little.
I don't know what DOC's are? My water has been excellent. PH=7.8 Ammonia=0 Nitrites=0 Nitrates=0
I have a filter box that contains 4 deep filter pads and 15 bags of crushed coral(for PH) it feeds a 7x7 planted pond. There is a 30 foot creek and a small waterfall into a 8x19x3 feet deep pond. I also have a timer hooked up to my pump that comes on for 1 hour every morning. It diverts some water to a sprinkler that waters my vegetable garden. Then I have an auto top off that fills the pond back to proper levels. Basically, small daily water changes.
I haven't had any brown sludge, just bubbles. I unfortunately think it was soap poured in out of malice, but can't imagine who would do such a thing. I was hoping there was some other explanation.
I am only happy to report that the fish seem well and I have most of it cleared up. Updated pictures along with a picture of suds in a white bucket.