lighting recommendations How much is too much light for the fish?

[Tanked]

How much is too much light for the fish?

I replaced the two 18” stock florescent fixtures on my 65 tall with a single 48” converted led shop light.  As expected there is a lot of wasted light and a huge increase in available light.  In the near future, I will replace the stock full plastic hoods with egg crate, or polycarbonate panels if I can find them cheap enough.  This of course will again greatly increase the available light.

Now the problem:  This is a low tech operation, so I don’t have the means to measure or adjust intensity. I’m using a 2 lamp fixture, and there is no diffusion. Each daylight 6000 K tube is focused straight down.  If I install the second lamp, it could be intense.

 When do you reach the point where there will it be too much light for the fish or low/medium light plants?  The ultimate goal here is a fully planted tank.

[Chiclid addict]

Form the research I did really quick just now this shouldn’t really be a problem but as usual more than one opinion is always good

[Dwayne Brown]

It really depends on the fish. For fish like neon tetras and endlers that really dint seem to care about their envirements it would be fine. However for fish like emporor tetras or catfish I think that light would be to much. One way I found to subdue light is to get duckweed or water lettuce to grow on the surface.

[CT_]

4 hours ago, Tanked said:

How much is too much light for the fish?

If the fish start to smoke dial it back 10%

[Carolina Guy]

My LED lights were too bright and too harsh for my taste, and also I was getting more algae growth in one of my tanks than I considered acceptable. So I bought a roll of fiberglass screen (charcoal colored) from a home improvement store (around $11 for a 36'X84' roll, and one can probably get shorter rolls than that). I cut some strips (it cuts easily with scissors) and placed them under the lights. This softened and diffused the light wonderfully. I think it was a big improvement aesthetically. I even doubled it on my Glowlight Tetra tank, the one with too much algae.

It could be my imagination, of course, but my fish seem happier--the Glowlight Tetras aren't staying hidden in plants nearly as much as they were--and my low-light plants (crypts and anubias) seem happier too.

This worked for me, but I have glass covers on my tanks. I'm not familiar with using eggcrate or polycarbonate panels, so I'm not sure if this would work for you or not. In addition, I have no plants that need a lot of light. (I figure, though, that a hole could probably be cut in the screen directly above any individual plant with higher light requirements.)

Like I said, I don't know if this would work for you, but perhaps it's something worth considering.

Edited March 29, 2021 by Carolina Guy

[Tanked]

5 hours ago, Carolina Guy said:

My LED lights were too bright and too harsh for my taste, and also I was getting more algae growth in one of my tanks than I considered acceptable.

I agree. Too bright washes out the colors.  This tank actually looked good with a small off centered light that gave the fish an opportunity to go over to the dark side when the need arose.

[Tanked]

13 hours ago, CT_ said:

If the fish start to smoke dial it back 10%

So steam is ok?

[Tanked]

17 hours ago, Dwayne Brown said:

One way I found to subdue light is to get duckweed or water lettuce to grow on the surface.

I 've been looking for an excuse to try some water lettuce.  Anacharis is the cover crop in my other tanks so far, There just hasn't been room.

[Dwayne Brown]

39 minutes ago, Tanked said:

I 've been looking for an excuse to try some water lettuce.  Anacharis is the cover crop in my other tanks so far, There just hasn't been room.

Another way is to take parchement paper and tape it on the bulb or string of lights to subdue it. This isnt perfect but it works.

[anewbie]

A bit depends on the fish. Some fishes are more shy or skittish under bright lights and will seek shady or less well lit areas of the tank. Others are less sensitive or prefer the warmth of a bright sun.