Guppy acting oddly

[Southpaw]

Hey guys, my male guppy has gotten pale in color and rarely leaves his hiding spot behind the heater. The rest of the guppies in the tank are perfectly normal. What could be the problem?

 

[Wolfsblood]

Tank size? Filtered? Heated? What are your ammonia, nitrite, and nitrate levels?

 

[Southpaw]

10 gallon, heated and filtered. Nitrate 20, nitrite 0. Temp is at 78.

 

[Wolfsblood]

Does he ever get picked on by the others? Any nips in his fins or anything?

 

[Southpaw]

None, the only physical difference is his color is not as vibrant

 

[Wolfsblood]

Hmm not really sure. Have you had him for long?

 

[Scottyhorse]

What's ammonia level? Tank cycled?