Thanks BuiDoi I'm leaning toward Lymphocystis from some of the pics I've seen while researching the problem, I thought it was Ich early but I've now ruled Ich out.
Here's some of Wikipedia's page on Lymphocystis:
Lymphocystis is a common viral disease of freshwater and saltwater fish.
Aquarists often come across this virus when their fish are stressed such as when put into a new environment and the virus is able to grow.
The fish starts growing small white pin-prick like growths on their fins or skin and this is often mistaken for Ich/Ick (Ichthyophthirius multifiliis) in the early stages. It soon clumps together to form a cauliflower-like growth on the skin, mouth, fins, and occasional gills. Lesions at the base of the dorsal fin are common among freshwater species of Central American origin, most notably Herichthys carpentis & inside the mouth of Herichthys cyanoguttatus & Geophagus steindachneri. On the tail fin of Koi, Carps, & US native sunfish (Lepomis sp.) On the side flanks of Walleye, Sauger & Flounder. On random head and/or tail areas of common goldfish, and oranda variants. This virus appears to present itself as a lesion(s) at differing locations depending on the species of fish being attacked, often complicating initial diagnosis.
The source:
https://en.wikipedia.org/wiki/Lymphocystis BuiDoi my nitrates are back to zero since adding the Zeolite but I think the 4-5 weeks of high nitrates prior to that might have been too long for the fish and caused a lot of stress.
If it was Ich there would be a lot more fish with the problem so I don't think it's Ich and the system has always had some salinity, it's never been below 0.5ppt for years and that steers me away from Ich and it's Wikipedia's cauliflower-like growth description and the pictures I've seen make me think it's Lymphocystis and if it is there's no known cure for that virus.
I'll keep reading up and you could also be right on a wound infection my son had a couple of fish caught up in a net while checking on them for size a few weeks back and it may have damaged a couple and because of the high nitrates anything could have happened. None of the fish doesn't show any of the visual signs associated with nitrate poisoning; loss of appetite; bottom sitting; pressed to the bottom; bent positioning; curled positioning; crooked spine; uncontrolled swimming or swimming in circles or the rubbing of Ich so I think Lymphocystis might be what it is.
They say don't stress the fish by chasing them around and knowing my luck I would need to net a lot of fish before I found the right fish, I'll put the camera down again today and see if it's only the one fish, I'm not sure if the second guy has a problem or not.
I've been checking the salinity 3-4 a day and bringing it up slowly making sure I don't take it too high and I'll take your advice and add some more Zeolite (in stronger bags this time)
Backyard Aquaponics
