New powder blue guarami is sick, need help!

I just got a a powder blue guarami for my tank last Friday. He was listless since i first put him in the tank, didn't eat much either. Now he is having difficulty swimming. He usually leans to one side, and stays put laying down. Occasionally he will get up and swim around for a few seconds completely normally, and then starts to lean and eventually lays down again.
The tank is 6 gallons. It has been up for about a year and a half. All other fish (which are a crowntail betta, oto, and two cloudy tetras) are perfectly fine. Parameters are normal.
I am not sure if this has anything to do with it since he was acting strange since I brought him home, but I just treated the tank with a copper liquid intended for killing unwanted snails.
I have relocated the guarami to a half gallon container and am treating him with Jungle Internal parasite Guard and a little bit of Melafix.

He just pooed in the hospital tank and it is stringy....so? parasites?

Sounds like parasites. Hopefully the Jungle meds will do the trick.

In the long term though, I'm not sure housing him with a betta is a good idea. They're both territorial, aggressive anabantids and as soon as his up and acting normal, I would be willing to bet you're going to get some serious fighting between the gourami and betta.

I think at this point....he is a total goner. I am going to back to the store I got him from and demand a refund for selling me a fish with parasites. I really liked the little dude too.

As for having a him with a betta, the betta poses no issue. He has been kept with gouramis, as well as many other types of fish and doesn't care who his tank mates are. I have also kept gouramis with a betta before in another tank for many years and never saw issues arise.

Well, I think if the betta were problematic he would have been already, but you never know how the gourami might react once it's in better shape to go picking fights. As long as we're talking anecdotes, I once put a male betta in a community tank with a dwarf gourami temporarily while I did some maintenance on the betta's tank. The gourami chased him around relentlessly. I would consider you lucky to have had no problems thus far.

You may wish to google.. Iridovirus and Colisa Ialia or "Dwarf Gourami Disease" I have always loved these fish ,but despite providing them with soft ,warm water with zero ammonia,nitrites, and nitrAtes no higher than 20ppm, I was never able to keep them alive for more than a few weeks,months.
Recent research suggests that as many as 22 to 25 percent of these imported fish carry this virus and that it is difficult to treat with any measureable success.
I am not suggesting that this is what is ailing your recent purchase ,just offering some interesting reading if you are so inclined.
Have heard far too many complaints with respect to this particular species for my own comfort and if your tank was larger,, I would recommend the "Pearl gourami" they are much hardier and can live up to ten years with proper care.
Is also reported by some, that the 'Honey Gourami" may not be as suceptible to the afore mentioned virus but I have no first hand knowledge to support this .

Thanks for the info.

Unfortunately, I had to euthanize the fish this morning. I thought for sure that he would have been dead by morning, but he was still alive, obviously suffering with no end in sight and it was apparent his condition was not going to improve.

I actually had a blue dwarf in another tank for many years, so I thought they were pretty hardy fish but I guess I just got lucky with my first one. I think I am going to stay away from guoramis.

I really like the snakeskin gourami, my husbands parents have one in their 55 and he has such a personality and an interesting primal look to him, but they get huge and would need to set up a much bigger community tank than I have in order to have one :( Someday...