Blinded Blackfins

[Kwenbee]

Oh..this aquarium stuff just gets better and better....

We set up the 20 gallon on Sunday. Water params are just about perfect already..0 ammonia; .25 nitrites. The zebras are happy as can be, swimming all over the tanks, as are the corys and the neons.

However, Fred, Scooby and Goldeen, the Blackfinned Tetras, who were the most active of all the fish in the 10 gallon seem to be very, very scared of the new light in the tank.

I bought a kit (tank, hood, filter, thermometer). The hood has a built in light fixture that came with a 15 watt flourescent bulb. The 10 gallon also had a built in hood, but had regular type bulbs, not flourescent. The 20 gallon is much brighter than the 10 (I'm assuming because it's larger).

I figured the gang would grow accustomed to the light, but the don't seem to be. If the light is off, they swim like normal, all over the tank. As soon as I turn the light on, they swim immediately under one of the plants in the tank and look very frightened. They used to attack the food at the top (was always afraid they'd leap right out on my hand), but now they hover under the plant...when the food drops past, they rush out grab the food and swim back under.

I can't imagine there is a smaller watt aquarium bulb than 15 watts, but I figure maybe there is a blue one I can purchase (headed to Petsmart tomorrow to see). Barring that, what can I do to darken the tank. It is a prefab hood...only one long flourescent bulb will fit in it. I cannot afford to go spend a fortune on a new hood just because the light is bright.

Right now, I've tilted the light section of the hood, so it actually is leaning against the feeding section of the hood, so it's not shining directly into the tank. They seemed to be a little more active by me doing that, but as soon as we turned the light off completely, they were totally back to normal...all over the tank, up to the top, etc.

Other than going to find some little fishy sunglasses, any ideas?

 

[astroguy]

try buying a few floating plastic plants. This will cut out the amount of light. With time (few weeks), remove the plastic plants one at a time.

 

[Kwenbee]

I thought of that, but I'm not sure it will change anything. Even with the light tilted so it doesn't directly shine in the tank, they hover under the plant.

I did realize this morning that the 10 gallon was in my daughter's room. Her room has pink walls. The new tank is in the living room, which has white walls. The 10 gallon also had black gravel, and the new tank has bright blue (went better with the colors in my living room). Could it be that between the white walls and the bright gravel, the flourescent light is just bouncing reflections and blinding the poor guys?

Would a tank background help? I am going to invest in the blue bulb (if they have it) and some plastic plants. Today, I took the light section of the hood off so that natural sunlight will get in through the plastic protective cover on the hood (the piece that covers the light from water splashes). The blackfins are swimming as usual and actually "smacked their mouths on the water" (my daughter's description) when we fed them. However, the neons still think it's night time and now THEY are hovering in the corner where they normally sleep.

Guess I gotta find Blackfin Raybans....

 

[ferret]

I tried to google for black fin tetras, but couldn't find a single thing. Are they black skirt tetras? If so, I know from research and past experience that they are very easily spooked, and generally prefer a dimmer light. They're natural habitat are South American rivers that are shaded from above by trees.

 

[Kwenbee]

Well, yeah...don't know where I got blackfin from, they are blackskirt.

So...do I now have to move them to a dimmer aquarium? My only option for dimmer light is to put them in the five gallon and maybe move the guppies to the 20.

Or will the backdrop/blue light work?

 

[QTOFFER]

I think a backdrop will help.

This is my theory: I think the fish are not being spooked by the intensity of the light per se. Instead, it is reflections of things both inside and outside the tank bouncing off the four interior glass surfaces that are frightening them. These reflections are more pronounced when the light is on. I think a backdrop will dramatically cut down these reflections and will also help absorb glare from the lights. HTH.

 

[Guest]

Qtoffer, good theory and advice.

The other thing I would say here is, give them time, they will adjust. It might even take a couple weeks, but they'll come around. The brighter light is just new to them, they'll get over it. My lemon tetras did much the same hing when they went from my rather dim 20 gallon, to my 90 gallon with 440 watts of light. That is not a typo, 440 watts! (Heavily planted tank). They hid alot at first, but now, eh, just another day at the office, swimming happily as can be.

 

[William]

My black skirt tetras did this when I changed their tank, they remained in the same sized tank and under same lighting.

Its just the change of scenery makes them very insecure, it will take them up to a month to establish their territories, soon they'll be back dashing around. It just takes time, they feel very insecure right now being thrust into new surroundings with no land ownership

 

[Kwenbee]

You know, that reflection thing hit home...they are VERY skittish when we walk up to the tank and they used to swim right over to us in the 10 gallon (because they thought it was time to eat).

I did replace the first bulb with one that said it was "50% blue light" and it is MUCH less glaring. It actually looks much better. I didn't do the backdrop yet, basically because I didn't like any of them at Petsmart. I also couldn't find any decent hideyholes for the bettas (everything had fairly rough edges and I worry about their fins).

The blackskirts (and I also learned at Petsmart that Goldeen is NOT a blackskirt, she is a goldskirt...well, I call her "she" but we have no idea what he/she is...she has a girl name so hence the she).

We did purchase new fish last night. We added to the neon population (we only had three survivors in the 20 gallon). We came home to a dead guppy, but put six neons in the tank with the remaining guppy, along with two corys.

We also added three zebra danios to the 20. The blackfins are still hiding when the light is on, swimming when it is off. I'm just ignoring them until they get used to the tank. We may check out a new lfs this weekend, and I'll look at backdrops there.

 

[grimlock3000]

I currently have sheets of white paper on my glass top that block out most of the light from my Coralife PC fixture. The fish are really active though, they spent over a month under the PC and apparently never fully adjusted to it