Colu

I think the antibiotics more about preventing secondary bacterial infections caused by the fungus damaging the skin so you could use maracyn2 instead of maracyn

Yes salt at that level will harm the plants I have no experience with killifish I just looked up that species and I can't find any information regarding salt tolerance you could use the co-ops treat protocol for fungal infections using maracyn and ick X instead of salt

saprolegniasas does have a high mortality rate even with the appropriate treatment it's a good that it looks smaller that means it's responding to the treatment fingers crossed for a good out come

The other in video look fine from what I can see hopefully salt and ick X with get on top of this

It could be an injury caused during shipping. and it starting to develop a secondary fungal infection I would treat with aquarium salt 1 table spoon for 2 gallons. and add one dose of ick X and let it marinate for 5 days. if it starts get worse give us an in 5 days i before then if it get worse

Does it have a fuzzy appearance i can't tell with your picture

Aquarium salt aids Gill function and adds essential electrolytes it's won't have a negative interaction with levamisole or praziquantel so it fine to use the to together I would just add a small amount of aquarium salt 1 table spoon for 5 gallons

Frist I would test your water parameters ammonia nitrite nitrate pH KH GH just in case something is off Looks like the start of a snout chondroma that symptoms of neon tetra disease. It's always possible something else is going it can remain dormant for long periods of time. it's only when a period of stress weaken the immune system that you start. to see symptoms it's caused by fish dieing and getting eaten ingesting to many pleistophora for there immune system to handle. it's highly infectious no none treatment available. typically when they start to show symptoms they can go down hill in a couple of weeks what i would do is add no new fish to his tank sterilise any nets or equipment to avoid cross contamination it can infect angelfish danios barbs goldfish guppies and other species of tetra I would air on the side of caution when it come to neon tetra disease if a fish goes down hill rapidly I would remove it and humanely euthanize it with clove oil to prevent it getting eaten that the only way to limit it's spread I would essential keep this tank in quarantine with no new fish till the remaining fish died from this tank and it has been fully sterilised that could be a long time depending on the progression of the disease @a date with nature

Malachite green the active ingredient in ick X is effective at treating saprolegniasas or you could do a methylene blue bath or spot treat him in his weaken state the stress of capturing him to do baths might push him over the edge

Looks like 1ppm of ammonia that would explain the Gill inflammation

Gill inflammation could be caused by the parasite damaging his Gills or ammonia. your reading is zero so that's less likely unless you had a spike and missed it. all medication are stressful to some degree. i would still keep going with the treatment protocol. you could try adding a small amount of seachems garlic guard to his food to try and stimulate his appetite see if that helps

With what your describing I would up to salt to level I recommended could be saprolegniasas that a water mold

Nitrofurazone is effective at treating some types of dermal fungus if the fungus is spreading I would up the salt to 1 table spoon for 2 gallons coupled with the nitrofurazone and kanaplex hopefully you will start to see some improvement

A little more information would be helpful. a picture will help with a diagnosis. what are your water parameters ammonia nitrite nitrate pH KH GH temperature. how long has it had the lump on it's lip.

Assuming your breeder are wild caught fry are F1 Maybe more generations in they will be more willing to except frozen

Have you tried transitioning the fry on to prepared food with any success

Melafix is a mild antiseptic treat I would use aquarium salt it also aids Gill function and adds essential electrolytes remember to only put back in what you take out so if you do a 3 gallon water change add 1 table spoon of salt back in

I would also add some aquarium salt 1 table spoon for 3 gallons that will aid Gill function and add essential electrolytes

What is your nitrate level. also an injury can also cause these black marks. from swimming into something in the tank. if you have a quarantine tank I would quarantine and add some aquarium salt 1 table spoon for 3 gallons and monitor for a week update if it gets worse before then

Weight loss and spitting food can be a sign of wasting disease you would want to treat once a week for 4 weeks with expel p black out the tank for 24hrs during treatment as the medication is light sensitive and do a thorough gravel vac after treatment to remove as many expelled parasites and eggs from the gravel if you only feeding flake I would also feed frozen brine shrimp daphnia a couple of times a week as well

any rapid breathing hanging out near the surface lethargy flashing spitting food out sunken belly

Fast as @nabokovfan87 suggested finishes the course of maracyn then I would holed off on any more antibiotic treatments I would also add some aquarium salt 1table spoon for 2 gallons that will help reduce any possible fluid buildup in the eye if you have live plants add 1 table spoon for 5 gallons for a week than give an update if your seeing no improvement

What are your water parameters ammonia nitrite nitrate pH KH GH temperature how long have you had them have your added any new fish to the tank recently any rapid breathing hanging out near the surface also ammonia burn can cause black patches that why posting your water parameters are important

Some fish will be less tolerant to salt from my experience epsom salt shouldn't harm your fish you could lower the level of salt to 1 table for 3 gallons for the next bath and add an extra air stone he could be stressed due to the salt bath and that's why your seeing the rapid breathing

looks like an injury with possible secondary fungal infections if it has a fuzzy appearance that's not showing on the picture what I would do is treat with ick X along with maracyn that an effective treatment for fungal infections