The remaining 2 gf are Ryukins and about 4 yrs old and have no signs of sickness. None of the fish had weight loss, red finns or signs of parasites. They were all between 1and 2 yrs old except for 1 Ryukin at 4 yrs. I sit very close to the tank at work and I would notice small signs of a couple of scales not laying flat on their chest between pectoral fins. Then the typical progression of water retention until the fish became week over a period of 2 to 4 weeks. No antibiotics helped, salt or methylene blue treatments. When they became too week I euthanized with overdose of Syncain powder. The tank is 150 g, 2 Oase 800 filters, external thermostat set at 76.5 F. 0 ammonia, 0 nitrite, 0 chlorine, less than 10 nitrates. Ph comes out of the tap at about 6.7 and rises to around 7.6 after 2 days. Water is a little soft here in NC and I add baking soda at weekly water change. The well was shocked by the plumbers using a packaged powered treatment. It threw all water parameters off. It took around a month before I was comfortable with the water again and for a return to normal water parameters again. The fire ants attacked the plumbers and plumbers fired up a torch and burned them. A few days later we sprinkled food grade diatomaceous earth near the well and no more ants. Some dead ants were picked up in the home filter for about a week or so. I treat for parasites once or twice per year. I have used prazipro, paracleanse in the past, and this year will probably use paracleanse then expel. Can't remember if I've used expel on the gf tank before. What I have started doIng differently since these fish deaths- only changing 25% instead of 50% water, always adding declorinator even though the well is normal again, breeder said to use Aqueon declorinator instead stead of Prime (i can't remember the reason), set up a tank to always use aerated and age water for every water change. Also I have changed their diets to reduce protein- live floating plants once per day, frozen brine shrimp or blood worms in morning and wheat-germ pellet soaked in vitachem for dinner. I am starting to restock now and will see if things stay good over months, but I can't think of anything else to do better and am open to all suggestions. There are pictures and video of the tank and gf @flamingfanny on Instagram from prior to the well issue which occurred in February.