Hi guys,
So a few months back I've noticed that my fishes are scraping off the aquarium objects. There was no white spots but laboured breathing so I've treated them with prazi gold, paraguard, prazi gold again. Throughout the treatment, 2 juvenile Dicrossus filamentosus died. The breathing seems to be fine after the treatment but there was still some scraping from time to time. I've used all of the bottles' contents which lasted around 4 weeks for each bottle (I'm assuming it's flukes which the net says need a 3 week period of treatment). I'm having a freshwater planted aquarium and the dosages that I gave was just the water column, without including the gravel as part of the volume needed to be treated.

So few weeks passed and the fishes seemed to be fine and so, I've just got another few juvenile Dicrossus filamentosus to stock my tank 2 days back. They were fine but this morning, I saw 2 of them breathing heavily again. The rest of the Dicrossus seems fine, including some of the new additions that was added. So far there is no flashing or anything right now.

I've noticed only juvenile fish are affected which probably is due to their weaker immunity. And probably I've not successfully treated my tank but just that the inhabitants that survived acquired some immunity against the disease. And today, I saw that there are some red-brown spots near the gills, not on it (It's between both gills, directly below the head; similar to our neck/chin area), and some fin rot for the affected fish only. Not sure if this case is related to the previous one. Any ideas on what I'm dealing with? I've just dosed prazi gold again but this time, with the gravel included as part of the dimensions since praziquantel is really tough to overdose.