Effect of light on fish?

[alexv1n]

Hi, I've had a 55 gallon planted tank for a few years now and it used to run on a bulky 110W of lights which is barely sufficient to qualify as "low light" for plants.

When I bought the tank it came with a "nice" lighting system of two 15W bulbs. I bought a 48" double striplight, which gave 80W. I put that and the two old bulbs so that gave me 110W. However these three fixtures covered the whole top and in order to get access to the aquarium, I had to remove the small lights to open the lid.

Finally I decided to upgrade the lighting system. I bought a 260W power compact fixture with four 65W bulbs (two were 12K daylight and two actinic blue). I decided to try it out and see how it works and if the actinic lights have no benefit for the plants, I'll change them to regular bulbs.

But anyway, since I did the swap, my fish seem to be stressed by the bright light. The only fish that still swims in water columns are a pair of dwarf gouramis. SAEs lie on the bottom most of the time but the most effect it seems to have on rummynose tetras. Their heads used to be very bright red colors well past their pectoral fins. Now most fish have just their nose red and some even lost most of the red.

Even danios hide in the plants. Clown loaches rarely venture out of a cave.

Does anyone notice such a drastic effect of the light on fish? Granted, we have just moved and I re-assembled the tank and had to cull out a lot of plants, so the aquarium isn't grossly planted right now. Most of the plants are ... Oh, wait. I'd rather attach a picture to show how the tank looks.

Right now I shut off the actinic bulbs to see if there is any difference.

Any comments/suggestions are welcome.

 

[Ems]

I don't have suggestions - but I just wanted to say your tank looks really good

 

[FisheyLisa]

That seems like it may be stressful. If all your other params are the same, and that is the only variable, then it must be, right? Maybe less wattage for a week or 2, see if it goes to more normal, then you'll have your answer.

How long has the aquascape been changed, I'd think if they weren't acclimated in a week or so, then it's the light. I changed everything into a different tank, and my fish didn't really act very different.

 

[RTR]

When I add fish to my higher light tanks (and they are not that bright, max ~3 W/gal), quite a number of fish hide in the plants for a week or more, most eventually settle down and act "normal". But the lighting is not nearly as bright as yours.

 

[alexv1n]

It's been about a month since we moved in and "redesigned" the tank layout. The tank had the old lights for this past month and fish were Ok. They did seem a bit more nervous than before the move, especially SAEs. But that's only when I'm around and making sudden moves, the fish gets spooked easily (which I didn't notice all that often before the move). But then I changed the light and everything is very different now

Anyway, I'll try to turn off the actinic bulbs for now and run only two remaining bulbs which will give me 130W, which is close to my old 110W behemoth, and see how it goes. I'm hoping that my plants grow bigger and shade part of the light so that I can turn it all up again...

Just I have read a lot about planted tanks and their light requirements but never the "fish horror stories" like that... Or maybe the fish just needs to get used to the light. Sun gives out way much more than my light, how does the fish survive in nature?

P.S. I have bought the light on eBay for under $100.

 

[YoFishboy]

I would take out one of each bulb type and start out with shorter light periods - then add one more bulb after a few weeks, then the last one after a few more. Then slowly increase the light period.

 

[Squealor]

It's funny that you posted this! I just changed my light from the 30w that the tank came with to a 110w compact and my fish are pretty freaked out, too. The gourami seems fine, but the cories and the tetras have been spending more and more time under the plants. Exact same problem! I feel like as each day goes by, they are getting a bit more adventurous and come out more. However, I've learned not to turn on the light at night so it doesn't go from dark to super bright! Did it once and I thought I was going to give them all little heart attacks!

 

[alexv1n]

According to my preliminary results, shutting off the two actinic lights does help. The rummynose tetras go out from beneath the plants a bit and danios got a bit more comfortable. I'll continue watching but at this time I'm not sure if it is just the total wattage that matters (130W vs 260W) or the fact that I turned off actinics. Maybe it was that weird blue light that stesses the fish rather than the amount of light?

Does anyone have any opinion on using actinic bulbs in freshwater planted aquaria? Is there any benefits? I remember reading somewhere that actinics are beneficial for plants but I can't be sure that is correct. I'd rather replace all my bulbs with 6500K powercompacts rather than having two 12000K and two actinics but before I do another investment, any opinion on this is welcome.

P.S. The reason why I have these bulbs and not other is that the light fixtures came with it. I didn't choose the bulbs, they were supplied in package. While it might make sense for reef aquaria, I'm not sure how well it applies to planted freshwater ones.