Pleco Is Sick ?

[alien-planet]

I think my pleco has some sort of a problem , to me it looks like it is losing its colour and there appears to be a white patch showing with redness on it as if its bleeding why ?

i have been trying to feed the bloody thing since i got it but so far no avail , i feed him algae wafers does not touch them so i try catfish pellets and still nothing eaten, try normal fish food flakes and pellets and not eating it then i try cucumber and lettuce with zucchini and NOT eating it WHY ? What am.i doing so wrong ? Water is perfect tempture and had a recent water change any ideas ?
I feed him every night when lights are out

 

[bluesword23516]

Try feeding in the day, he might be asleep.  
It also sounds like he got a scratch or a cut and its infected.  I am not sure what medication you should use. Sorry

 

[alien-planet]

Hes defo non active in the morning mostly around 7pm when hes active and out his hiding spot.

 

[WILDER]

Size of tank in gallons or litres?
How many fish and which type?
Water stats in ammonia, nitrite, nitrate, and ph?
 
The white patch does it look bleached out, or fluffy like cotton wool?
Where are the red patches are they inside the white area, or outside?
 
Can you isolate the plec for treatment?