Sorry I have not been in touch and its time for an update. My husband changed the 2 outlet into a 4 electric outlet unit for running extra pumps. I realigned loose walking slabs around the pond for our safety. The water is very clear since the total clean out. We did not remove the algae that was growing on the pond sides. Six black comets have survived. They had the greyish slime and ick. I used Tetra Pond fish treatment and treated for 600 gallons, added treatment for 50 gallons a few days later. My pond is 1000 gallons. As the days progressed the grey stuff disappeared and the ick dwindled to a few dots on the tails and bodies of three fish that were infected. I have been testing the water every 3 days and today’s readings are: Nitrate is at 0 Ph is 8.5, Ammonia 0 Phosphate at 2. I tested our drinking water and it is at 2.00 with gunk that shows up after 5 minutes. I will place the new UV purifier unit and filter into the pond with a 300 gph pump tomorrow. Aeration is provided by two pondmaster 1800 gph pumps, geyser spray upright and the other sprays sideways. The fish are actively swimming and hungry. They are fed sparingly twice a day and allows me to do a visual inspection. Two frogs have returned to their home. My water lilies are doing OK in the pond. The other plants are still quarantined. I bought a shop vac, it is dedicated for pond use only. It has a drain and my husband will put a wire mesh on the nozzle so it won’t suck fish up. Every 4 weeks or as needed so the stuff wont have chance to turn to muck. I appreciate all of your suggestions, expertise and support. I miss my fish but very thankful for the survivors.