Is It Possible To Have Too Much Light?

[rdd1952]

I have 130 watts (2 x 65w power compacts) on my 29 gallon so I'm over 4 wpg. It seems that ever since I put those lights on, my tetras don't come out as much. But at night when the lights go out, the tetras are all out swimming around. I can cut the lights back to just 65 watts since there are 2 switches (one controls a light only and the other controls a light and the fans) but that will give me just barely 2 wpg. Has anyone else experienced anything similar to this?

 

[Tokis-Phoenix]

Im not sure wether fish can have too much light, but when you look at the facts it does seem they don't enjoy too much- i think the length of time you have your tank lights on rather than how strong they are is what is most important;
a. Most fish can live entirely without tank lights.
b. Turning tank lights off when fish are sick can lower their stress levels, soo...
I don't know much on tank light power, but if your tetras behavior has changed alot since you changed lights and nothing else, they might not be enjoying the power of the lights that much- how long has it been since you upgraded lights and how long do you leave them on for each day?

 

[rdd1952]

I actually upgraded back in the summer. I can't remember if they became "shy" immediately after the upgrade or not but have noticed in the last couple months that they do come out much more after the lights go off. My lights are on for about 10 hours a day, 4 in the morning (6 - 10) and 6 at night (4 - 10) so they're actually off more than their on. I will probably experiment with leaving the one light off for a few days/weeks to see if it changes their behavior.

 

[lovell_89]

from what i've read about tetras they like subdued lighting, maybe thats why they seem to hide more.

 

[Durbkat]

Yeah tetras hate bright tank lights, when my black widow tetras were in my 20g the tank in the 20g is bright and they never came out and swam around until the lights went out then they swam alot but when I put them in the 55g its light isn't as bright compared to the 20g lights and they now have come out of hiding and swim around alot more and they proboly will come out more once I add more tetras so if you can lower the wattage of the lights I bet those tetras will swim around alot more.

 

[rdd1952]

My black phantom tetras in the 75 gallon are always out swimming around and it has 260 watts (4 x 65) so it's almost as bright as the 29 gallon. I also want to add more tetras and get both the serpaes and pristellas up to 8 each.

 

[Fishkeeper2004]

I suggest if you want to see your tetras throughout the day more active while the tank light is on, introduce some floating plants, so in some areas there is shade within the water.

 

[fishing4exotics]

It might be that the tetras preffer low light. Adding cover will encourage the tetras to hide. rdd1952 do you have any live plants in the tank? ?Sounds like the lights you have are what is needed for a planted tank.

 

[rdd1952]

It is a planted tank. Mainly Amazon Swords, Anacharis, Anubias Nana, Java Ferns and Hygrophilia (I think that's it).

 

[fishing4exotics]

Sounds like a beautiful tank! Post some pics

I have had fish that became more timid when they are placed in a tank with lots of cover, such as plants. The same fish in a bare tank would swim out in the open. The serpaes and pristellas you plan on adding to the tank might work as dither fish and bring the rest of your tetras out in the open.

 

[CFC]

All fish dislike bright lights, in nature they are most at risk from predators during the lightest hours of the day and most fish will head for deeper water or places shaded by terristial or aquatic plants until the sun goes down. In a tank they cannot go deeper and shaded areas are not so available so the fish will show visable signs of distress. Im afraid when it comes to the lushly planted dutch style aquariums you really have to make the choice between fish and plants as the two dont really work together, its either a heavily planted tank with bright lighting and CO2 with just a handfull of some tiny fish which can easily use shaded areas or a normal tank with maybe a few hardy plants and standard lighting.