my Brochis splenden is not eating.



Is it internal parasite?1. Water parameters
a) Temperature range. - 26-27degC
b) pH. - 7
c) GH. - unknown
d) KH - 4dkH
e)Ammonia - 0, Nitrate - 20ppm, Nitrite - 0
f) Water change frequency - 25% weekly
2. Tank set up
a) Size. - 24" X 12" x 14"(height)
b) Substrate. - dennerle quartz gravel
c) Filtration. - eheim 2222 with sponge filter
d) Furnishings. - a Nana plant attached to driftwood + java moss tie to driftwood
e) Other tank mates. - 5 C.aeneus , 3 C.sodalis
f) How long has it been set-up? - 2 years ++
3. Symptoms / Problem description
My new 2inches B.splenden is
- Not eating. Doesn't react much to food. (Hikari corydoras pellet, frozen bloodworm)
- Its color appears a bit darker than other B.splenden.
- Not responsive.
- No sunken eyes or belly
4. Action taken - None
5. Medications used - None

Question: What medication is good for this situation? Will melafix, pimafix or jungle parasite clear help with internal parasite?
Please advise.

Thanks in advance!