Finally Stumped (for good?)

[SourAngelfish]

Tank has been up for around a year now, it’s a 120 fowlr with 30 gal sump. I’ll need to get back with a water test tomorrow but last time I checked, all was good. I buffer the water regularly. I am aware that a water test may be key to figuring this out though.

Issue: all of my fish have been through 3 months of copper (checked with Hanna copper test), 3+ rounds of prazipro, and are still flashing on rocks. It had been going on for maybe another 3 months and so I just now finished up dosing 3 more rounds of prazipro. Fish still flashing.
Even more odd are the hardy fish like my grouper flashing and less hardy fish like my Angel do not. It’s causing a lot of confusion for me. What could be causing them to flash?

None of the fish show signs of ich either, so I suspected flukes but now I have no clue after 3 straight rounds of prazipro.
Sometimes my Angel gets cloudy patches on it’s skin, but I can only assume it’s from the occasional scratch. Any advice is very much needed.

 

[SourAngelfish]

It’s also worth noting that all of the fish eat like pigs and are thick and far from malnourished. The only damage they show is occasional scratch from flashing, it’s very frustrating

 

[Jay Hemdal Verified Community Expert]

It’s also worth noting that all of the fish eat like pigs and are thick and far from malnourished. The only damage they show is occasional scratch from flashing, it’s very frustrating

Hi, I sometimes see "idiopathic scratching/flashing" that seems to be behavioral, and not caused by a specific disease. However, that is typically seen on one or two fish, not a group of them.

My guess is that the tank has a chronic fluke infestation. The only thing pulling me away from that diagnosis is that you report that none of the fish look "tattered" or have secondary symptoms. Still - in some tanks, the fluke population reaches a sort of "balance" and the fish never progress to showing secondary symptoms. This happens the most with gill flukes.

Prazi can be tricky to dose. It does not kill fluke eggs, so you need to time the repeat doses very carefully. I generally suggest redosing after 10 days. The second issue is more important: when you dose prazipro, bacteria populations develop in the tank that feed on the prazi and the glycol solvent as their food source. Subsequent treatment on the same tank become ineffective because the prazi is consumed faster than it can work. These bacteria persist for some time, rendering that medication useless for that tank.

The option that I've come to use is hyposalinity for 35 days. You don't need to go as low as you do for marine ich, I generally suggest a specific gravity of 1.012. Of course, you cannot do that if invertebrates are in the tank.

Jay

 

[SourAngelfish]

I’m ruling out flukes now, have dipped several fish and no sign of flukes. Angel has the appearance of skin sloughing off and it almost looks identical to brooklynella. This could possibly explain how it got through a full copper treatment. Will metroplex in food kill brook? To be quite honest I have not tried the metroplex approach in full force. Should I dose the water or just feed?

 

[SourAngelfish]

I’ve experienced velvet before, and I’d say it looks more similar to velvet far more than ich. The thing is, if it were velvet, I would have 100% lost my tang/puffer by now

 

[SourAngelfish]

I should mention water tested near perfect, 8.2 pH, 9 alk, 0, 0, on amm and nitri. Nitrate was around 100ppm maybe higher though…could be an issue but I have no pest algae’s. Salinity was at 1.024. I have a temperature controller connected on my heater keeping it constant between 77-78.