Yes a couple avenues. He looks very bad though.
First do a series of water changes even though the water is alright. An actual number for all of the water parameters is best to have...
For
Ammonia
Nitrite
Nitrate
pH
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nice to have if available
GH - aka (General) hardness
KH - Carbonate Hardness aka Alkalinity
TDS if you had that -not absolutely nec.
He is in a delicate state and dramatic changes could also kill him.
Check/test water quality asap, but even if you can not test it, do pwc with treated water, preferably like Prime which will help if water parameters are not in the safe range.
Safe would be
Ammonia 0
Nitrite 0
Nitrate up to about 40, for a sick fish less than that is even better.
Water changes if water parameters are safe-
(why pwc are done this way - explanation is towards the end)
~1G, then do one more 1G, (called back to back partial water changes, always temp checked and not cooler than the tank water)
later, appx. 2 hours to 8-12 hours -(later, like overnight or after getting home from work,) another 1G back to back pwc (1+1=2G)
Next day the same thing
1G back to back pwc then same as above wait a while and do it again - 1G back to back pwc. 2G plus 2G by the end of the day
>>>>>>If the water parameters aren't safe
, **You can do the pwc back to back again, Test if you have the test kit, if the water quality is not safe, do another back to back pwc until it is safe. In an urgent to emergency situation just keep going until it is safe.
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If you have a vac for the substrate it would be great to use that for the pwc.
****
The reason behind back to back pwc, is to change the water quality the fish is in, in smaller increments, in hopes his weakened system can keep up with the changes.
Without doing weekly pwc, the minerals in the water increase with top offs for evaporation, making a more concentrated water in the tank, even though the water is clear, it is increasing in TDS - Total Dissolved Solids. The fish's system will try and keep up with the higher TDS and sometimes it causes stress, .
A 80-90% pwc all at one time is a very sudden change for the fish and when ill/unhealthy condition, his osmotic regulation may not work very well, and since your fish seems pretty ill, the less drastic change is better.
On the bright side, after doing back to back and pwc of around 8 - 10 gallons, you have pretty much freshened up all the water, and doing large pwc like a 50% pwc in the future will not be much of an issue, if you keep up with a 25-33% weekly pwc changes.
So if there is unsafe water quality at any time the priority is to get the water safe for your fish!!!
Often the fish just needs a bunch of fresh clean (treated - treated meaning dechlorinated, if ever it is not mentioned, it is implied that water in a pwc is always treated for chlorine, chloramines and heavy metals with a treatment product) water and the fins will start to heal.
Sometimes just getting the water parameters the best possible quality will help the fish be able to use his immune system to to fight infections and begin to get well.
If he does not seem to perk up a little after the first to second day, or if he seems even worse after getting the water changes going he will need medicine.
As a sidenote, you mentioned having this fish only about a month.
Are you familiar with the nitrification cycle? If not, you can read up in the link in my signature, for Getting Started, an article which will help you with lots of important information.
Do not rinse the filter pad in untreated water. It will kill the beneficial bacteria (BB) you need for nitrification. You can rinse or swish it around to get out debris in pwc tank water or fresh treated water. The filter pad is where the greatest amount of BB grow.
So sorry that was a lot to throw out there to you.