14k vs 20k

[daniella3d]

Why don't you try switching them and see if the fish now will congregate on the other side? I am skeptical. I never saw a difference in behavior from changing the wavelength of my MH light. I do see a difference when the MH goes off and there is only the actinic. My copperband does not like strong light so when the MH goes out he's out.

It could be that your 14k light is just lower in intensity and the fish feel more secure. Or it could be just a coincidence. In any case, if you switch them and then the fish go on the other side to go under the 14 again, then you will have something.

Originally Posted by phreezee

I run 20k 25oW MH and the other day one of them burnt out. I had a 14k bulb handy so I replaced it for the meantime and noticed they fish really like the 14k side a lot more. All of them would congregate to the 14k side and just swim in circles there.
I never gave any thought to what fish prefer until I noticed this. Anyone else experience this?