Fish 'Can' see colour.

After changing over from flourecent. To. LED lighting, I was having a real time of it deciding what colour to select in one of the tanks. The white cloud and other mountain Minnow were proving to be a tad shy that day and I tried firstly to dim the light. No affect. Blue? They came out a little but not far. Green? They ventured a little further. But shot under cover again after a quick look around. Then..I selected red. One by one, out they came one and all. This time rising high to the mid water position, curiously swimming about and very keen to explore. I made various movement to see if would put them off but it did not. I then switched back to other various colour settings and off they went. I repeated this a lot. And it was and has remained the same reaction every single time.
End.

Many aspects of lighting has been demonstrated for many fish species as having an effect on behaviour, development and sometimes even growth as well as many other things;

Heydarnejad, M. S., Fattollahi, M., & Khoshkam, M. (2017). Influence of light colours on growth and stress response of pearl gourami Trichopodus leerii under laboratory conditions. Journal of ichthyology, 57(6), 908-912.

Karakatsouli, N., Papoutsoglou, E. S., Sotiropoulos, N., Mourtikas, D., Stigen-Martinsen, T., & Papoutsoglou, S. E. (2010). Effects of light spectrum, rearing density and light intensity on growth performance of scaled and mirror common carp Cyprinus carpio reared under recirculating system conditions. Aquacultural Engineering, 42(3), 121-127.

Karakatsouli, N., Papoutsoglou, S. E., Panopoulos, G., Papoutsoglou, E. S., Chadio, S., & Kalogiannis, D. (2008). Effects of light spectrum on growth and stress response of rainbow trout Oncorhynchus mykiss reared under recirculating system conditions. Aquacultural Engineering, 38(1), 36-42.

Huntingford, F. A., Adams, C., Braithwaite, V. A., Kadri, S., Pottinger, T. G., Sandøe, P., & Turnbull, J. F. (2006). Current issues in fish welfare. Journal of fish biology, 68(2), 332-372.

en Acuicultura, P. D. T., & Buenaventura, V. (2020). Effects of different color artificial lights on growth, survival, and sex ratio on an experimental population of freshwater ornamental emperor tetra fish Nematobrycon palmeri. AACL Bioflux, 13(2).

Stevens, C. H., Croft, D. P., Paull, G. C., & Tyler, C. R. (2017). Stress and welfare in ornamental fishes: what can be learned from aquaculture?. Journal of Fish Biology, 91(2), 409-428.

To document a few.

I personally just use a regular bright LED light. I don't mess around that much with color.

Yep I get that and as a rule I don't either excepting when I have a suspicion of possible ick or want to see if the fish are healthy. Having lured out the shyest critters out into the open I can zap the light to red and get a better eyeball.

Mr Tomato said:

Yep I get that and as a rule I don't either excepting when I have a suspicion of possible ick or want to see if the fish are healthy. Having lured out the shyest critters out into the open I can zap the light to white and get a better eyeball.

Click to expand...

I mean.. white

Mr Tomato said:

Yep I get that and as a rule I don't either excepting when I have a suspicion of possible ick or want to see if the fish are healthy. Having lured out the shyest critters out into the open I can zap the light to red and get a better eyeball.

Click to expand...

Oh, that makes sense. I guess I never knew that red light could give you a better view of suspected inch.

Typo. Meant white . The red light was to lure them out. Does it make sense now lol

Looking for ich

Mr Tomato said:

Typo. Meant white . The red light was to lure them out. Does it make sense now lol

Click to expand...

Sort of...

I heard that fish can't see red light or something, and that nocturnal fish owners like to use red to see their fish(that could all be fake, idk)

That doesn't sound correct, because the light is still there, but it might give a more "shaded" or "sunset" look and they feel more comfortable coming out?

Most aquarium fish in the wild would never be exposed to light as bright as our aquarium lights and prefer dimmer lighting and shade

When I turn on the blue light, the fish begin to go into sleep mode, but they certainly can see it. If the tank goes from dark to blue too suddenly, it can spook them. Red works better with nocturnal fish in my experience. I only ever see some of my nocturnal fish if I turn on the red light. And it doesn't spook them like the blue light does. They can still see it, as far as I know. It just isn't as intense as a day light. Even so, I don't ever bother with blue/red lights. Just the standard day light and then it's off at night.