Fish Changing Color

[DanielKeepsFish]

So, i bought a red tail shark and a dwarf gourami today. Everything is great, they are getting along and are very active, bacteria has colonized, however, when i was at the store, the red tail shark's tail was more white than any other color, and after a few hours in my 20H tank, the tail turned red. Im guessing thats a good thing because it is a 'red tail shark' but I'm just wondering. (Also, i know the red tail is semi aggressive, i have a 40 gal tank that has more compatible fish i'll move him to when he gets about 3-4 inches.) 
 
One more question, the neon dwarf gourami seems waaaaay more active at night than in the day. (I'm typing this at 10:00 pm) 
 
Thanks for reading my post! 

 

[Goggy]

your red tailed shark is fine.
 
I have no idea what time of day are dwarf gourami usually active but remember, these gourami do live in asia as jetlag (my theory) could be whats happening

 

[DanielKeepsFish]

Okay, thanks for the info.

 

[AshleyNZ]

With my RTBS (Red Tailed Black Shark) the colour of his body and tail would turn pale, and this would indicate stress. Since you've said his colour in his tail went from pale to bright, that means he's settling in well  

 

[DanielKeepsFish]

Cool, the people at petco did have him in a tank with some much larger catfish and bala sharks. He was probably not getting enough nourishment or space to swim around in.

 

[Tongue_Flicker]

Recent water changes, stress, too bright light, quick exposure to bright light (at night) causes normal color changes.