Ok so I lost my 4" green terror, in which I started paying closer attention to my oscar who is the only fish left. After the green terror died about a week later my oscar stopped eating, naturally of course he is now looking thinner from not eating.

What I have found:
I noticed some small rounded worms wiggling like a snake, looked metallic, like a metal shaving swimming in the water, I quickly netted one out and it looked bigger at the top im guessing the head which was black and the smaller part the tail I guess was a white color. After looking closley for these worms I found at least 20 or so swimming around. I treated the tank with wardleys ick away and it seems to have killed off the small worms.

My oscars behavior:
My oscar doesnt have any external problems other than his odd behavior such as swimming head first into a corner then slowly swimming sideways on his side or sometimes even upside down along the bottom of the tank towards the center along with some seizure looking fits every once in awhile. He also has almost a twitch to him around his mouth also that occurs randomly. Another odd behavior is i have caught him swimming backwards sometimes for almost the whole tank length wise. I have noticed his feces are like a white stringy glob looking substance. And he wont eat ANYTHING.

What I think it is:
But upon searching the internet I found out about Hexamita which causes hole in the head. "Symptoms: The first symptom of slimy, white mucous feces, even while still eating and acting normal. Further signs are the fish hiding in the corner it's head down, head above the eyes gets thin, they blacken in color, and swim backwards."

Now most of the symptoms fit my oscar, such as the white mucous feces, head above the eyes gets thin (Although I cant be sure on this one since he hasnt been eating) and swimming backwards. I have a red tiger oscar so im not sure on the blackening in color either, but he seems no darker than normal.

I have purchased a product called Parasite Clear Tank Buddies which claims to clear external and internal parasites fast. It also includes the ingredient "metronidazole" which is recommended for treatment of hexamita. I lowered my tank water to 40 gal (I have a 55gal tank) for easier treatment with the dissovling fizz tabs (8 come in a box, 1 per each 10gal of water, so I could get 2 doses per box) and have put in the first dose today.

My water quality is in spec as it always has been, I have lost my green terror who was the newest addition to my tank and DO NOT want to lose my Oscar. He has not eaten for 6 days now and I am very worried about him not having any nutrition whatsoever. The last thing he ate was a goldfish that I tried to coax him into eating since he had stopped eat but after 1 goldfish he wouldnt touch another.

Now what I need to know is if I am on the right track to getting my oscar healthy again. If not what do I need to do? Can anyone explain to me what the metallic worms were? Please respond asap as me and my oscar need help. Thank you for reading and your possible advise.

first of all, we need water parameters: ammonia? nitrite? nitrate? pH? and water temp?
saying perfect water means nothing to us... we need those parameters.

there are times treating the tank make the fishes refuse foods for a week or two....
and giving gold fish which i am sure you did not quarantine put your o at risk
of poisoning and other fish illnesses the gold fish may has.

having lost another fish in the same tank means you have water issues.

Nitrate: 35
Nitrite: 0
Ammonia: 0
pH: 7.4
Water Temp: 82.3

And no the goldfish i offered him werent quarantined, I have a 10 gal tank I use as a feeder tank they normally are quarantined before he gets them but i was just trying to get him to eat something.

Your description of the excrement alone leads me to believe it's an internal parasite, as you have stated. The little worms swimming around are most likely your common planaria worms, which are harmless. I believe treating your fish in a hospital tank is the best option. Maybe converting your quarantine tank into the hospital tank. The medications will have a negative effect on your bacteria colony. Possibly leading to recycling the aquarium. I wouldn't panic at this point. Fish can go weeks without food, because you have already gone the medication route, continue to do so. I would also advise you to utilize an air stone in your aquarium especially while treating with medications, they can sometimes deplete the oxygen content of the water.

The 1st treatment you used for ick would probably have not done much good for internal parasites. your 2nd treatment sounds a more suitable med. check the instructions to see if it harms you filter?

I can't really say what the worm would be, the world is full of small worms and without seeing one and instantly recognizing it I would be at a loss without an expert. my guess would be as you have an internal parasite. so your treatment would be correct. there are a number of small worms that can sometimes get into a tank and be harmless though. most likely cause of infection would be your feeder fish. this is why a larger number of members don't use feeders. feeders are kept in poor conditions as they are cheap and not worth the cost to maintain them correctly. I would consider a diet change for your fish.

is this the fish we are talking about????
there are some medicine that make the fish refuse foods for sveral days.
melafix is one of them...having applied a medicine, probably that is the
culprit.

i would suggest a regular water change to keep the water in-check while
analyzing the situation....pristine water is the best anti dote for most
fish illnesses.

give them any live food lately?

Thanks for all the input, Yes the picture of the oscar is the fish I am talking about, the picture is only about 3 days old. If he recovers which he is doing much better now, no shaking or seizure like fits that I have seen and he ate 1 super worm I tried. So its deffinatly a start that he finally ate something! But he will deffinatly have goldfish cut from his diet. He has been treated with metronidozole for 2 days now. And also Paul he wasnt eating before I started him on any medication. Well im off to change some water. Ill keep you guys updated on his progress, and thanks for the help thus far.

Well he has eaten maybe 3 crickets and 1 super worm since the last time I posted. After 7 days of the Metronidazole treatment I havent seen any of the seizure like fits, I have been changing the water regularly and put in a new filter and he still isnt eating, although sometimes he acts like he wants to eat and if I drop something in he will swim up to it but wont eat it. Is there anything else I can do at this point?

If you are done with the treatments, place carbon in your filter for a few days... this will remove any left over meds... Then remove carbon.

the meds will often make them refuse their food for a bit... a week after meds is not uncommon...

if u just wanna get some calories into the fish, i suggest trying bloodworms(preferably live ones). in my experience, bloodworms are the most tempting food to any carnivorous/omnivorous fish. they smell so good to them, they just cant resist unless theyre really sick to the point that they wont even go near food. even my pickiest batch of betta fries would instantly wean off BBS for chopped bloodworms. besides, another bonus is that bloodworms are small, and considered 'bite size' for any oscar. they dont require much chewing and so ur oscar wont hesitate to eat them.
its just an idea, it might or might not work but it is worth a desperate try..

Where are live bloodworms avaliable, I dont think I ever seen any besides frozen cubes and the freeze dried ones.

Also I did add carbon to the filter after the water change when I stopped the medicine.