Fish Are Losing Color

[targa66]

I tried to do a search on this but can't narrow it down...

My black swordtail seems to be losing color - he was a very jet black uniform color and now the top of his head is definitely paler. He's otherwise healthy, chasing the girls and eating. Stats in my tank (156 litre) are all top notch. There's several of his offspring in the tank and I think some are also getting washed-out looking like him. Other fish in the tank (guppies, neon & rosy tetras, orange female swordtails) are all unaffected as far as I can tell.

Only change to the tank - about 2 months ago I started using one of those Tetratec CO2 systems. I don't use it everyday but it has made a big diff. to my plants. Could more CO2 in the water make the fish paler??

Any thoughts?

thanks,
Shelly

 

[kenny92]

if it is the tetratec system it will probably just be the fish getting used to changes in their enviroment, i dont think it will stay like that.